Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101660
Nan Xin , Yilong Zhang , Yifei Li , Guihua Tang , Yinan Nie , Yang Hu , Min Zhang , Xin Zhao , Dian Huang , Hao Shen
Thermoelectric (TE) materials have great potential in the energy recovery and environmental protection. Single crystal tin selenide (SnSe) demonstrates advantaged TE performance across a broad temperature range, but it is easy to form mechanical cracks and difficult to apply in devices. Poly-crystallization effectively enhances its mechanical properties but severely limits the hole transport reducing TE performance. Here, we provide an efficient strategy to increase hole concentration and introduce intermediate band for enhancing the electrical performance of polycrystalline SnSe in its advantaged temperature range via Al/Na co-doping. Specifically, Na dopant increases the hole concentration from 2.60 × 1017 cm−3 to 1.20 × 1019 cm−3, while Al dopant introduces intermediate band to reduce the thermal excitation temperature and promote the hole transition. As a result, the power factor of Al0.01Na0.01Sn0.98Se reaches to 10.78 μW cm−1 K−2 at 823 K. In addition, we used the volatilization of carbonate to introduce dislocations and point defects in SnSe. The multi-scale defects effectively scattered phonons, making the thermal conductivity of 0.39 W m−1 K−1 is achieved in Al0.03Na0.01Sn0.96Se. Benefit from the optimization strategies of both electrical and thermal performance, a state-of-the-art peak ZT of ∼1.73 is achieved in Al0.01Na0.01Sn0.98Se. This work reveals the key roles of intermediate bands and dislocations in regulating the thermal excitation temperature and anisotropic thermal conductivity of SnSe, and it provides a new idea for improving the TE performance of SnSe-based materials.
{"title":"Boosts thermoelectric performance of Al/Na co-doped polycrystalline SnSe via intermediate band and multi-scale defect engineering","authors":"Nan Xin , Yilong Zhang , Yifei Li , Guihua Tang , Yinan Nie , Yang Hu , Min Zhang , Xin Zhao , Dian Huang , Hao Shen","doi":"10.1016/j.mtphys.2025.101660","DOIUrl":"10.1016/j.mtphys.2025.101660","url":null,"abstract":"<div><div>Thermoelectric (TE) materials have great potential in the energy recovery and environmental protection. Single crystal tin selenide (SnSe) demonstrates advantaged TE performance across a broad temperature range, but it is easy to form mechanical cracks and difficult to apply in devices. Poly-crystallization effectively enhances its mechanical properties but severely limits the hole transport reducing TE performance. Here, we provide an efficient strategy to increase hole concentration and introduce intermediate band for enhancing the electrical performance of polycrystalline SnSe in its advantaged temperature range via Al/Na co-doping. Specifically, Na dopant increases the hole concentration from 2.60 × 10<sup>17</sup> cm<sup>−3</sup> to 1.20 × 10<sup>19</sup> cm<sup>−3</sup>, while Al dopant introduces intermediate band to reduce the thermal excitation temperature and promote the hole transition. As a result, the power factor of Al<sub>0.01</sub>Na<sub>0.01</sub>Sn<sub>0.98</sub>Se reaches to 10.78 μW cm<sup>−1</sup> K<sup>−2</sup> at 823 K. In addition, we used the volatilization of carbonate to introduce dislocations and point defects in SnSe. The multi-scale defects effectively scattered phonons, making the thermal conductivity of 0.39 W m<sup>−1</sup> K<sup>−1</sup> is achieved in Al<sub>0.03</sub>Na<sub>0.01</sub>Sn<sub>0.96</sub>Se. Benefit from the optimization strategies of both electrical and thermal performance, a state-of-the-art peak <em>ZT</em> of ∼1.73 is achieved in Al<sub>0.01</sub>Na<sub>0.01</sub>Sn<sub>0.98</sub>Se. This work reveals the key roles of intermediate bands and dislocations in regulating the thermal excitation temperature and anisotropic thermal conductivity of SnSe, and it provides a new idea for improving the TE performance of SnSe-based materials.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101660"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101662
Xinli Ye , Yuxin Zhang , Jianqing Xu , Shan Li , Xiaomin Ma , Linglin Cao , Junxiong Zhang , Xiaohua Zhang , Kai Zheng
Due to the limitations in structure and loss mechanisms, achieving both excellent reflection loss and broadband electromagnetic absorption simultaneously has been challenging for SiC-based materials. In this study, an innovative approach was adopted to fabricate Al2O3-modified SiC (SiC/Al2O3) ceramic matrix composites by polymer impregnation and pyrolysis method, and oxidation of a carbon framework. Through structural engineering, the introduction of Al2O3 phase established different loss mechanisms, such as dielectric loss and conductive loss. During the X-band (8.20–12.40 GHz), the resulting composite achieved a minimum reflection loss (RLmin) of −50.52 dB at a thickness of 2.20 mm, with an effective absorption bandwidth (EAB) of just 2.28 GHz. Building upon this foundation, two different periodic metamaterial structures were designed to optimize the electromagnetic absorption performance of the SiC/Al2O3 composite. By employing a multi-scale design strategy, significant improvements in both RLmin and EAB were achieved innovatively. The cross-shaped structure achieved efficient absorption across a frequency range of 8.20–12.40 GHz, reaching an RLmin of −78.69 dB and an EAB of 3.32 GHz at a total thickness of 2.80 mm. This research provides a novel approach for designing advanced SiC-based metamaterials with excellent radar stealth performance in the X-band.
{"title":"Synergistic enhancement of radar wave absorption in SiC/Al2O3 composites via structural tuning, composition optimization, and unit design","authors":"Xinli Ye , Yuxin Zhang , Jianqing Xu , Shan Li , Xiaomin Ma , Linglin Cao , Junxiong Zhang , Xiaohua Zhang , Kai Zheng","doi":"10.1016/j.mtphys.2025.101662","DOIUrl":"10.1016/j.mtphys.2025.101662","url":null,"abstract":"<div><div>Due to the limitations in structure and loss mechanisms, achieving both excellent reflection loss and broadband electromagnetic absorption simultaneously has been challenging for SiC-based materials. In this study, an innovative approach was adopted to fabricate Al<sub>2</sub>O<sub>3</sub>-modified SiC (SiC/Al<sub>2</sub>O<sub>3</sub>) ceramic matrix composites by polymer impregnation and pyrolysis method, and oxidation of a carbon framework. Through structural engineering, the introduction of Al<sub>2</sub>O<sub>3</sub> phase established different loss mechanisms, such as dielectric loss and conductive loss. During the X-band (8.20–12.40 GHz), the resulting composite achieved a minimum reflection loss (RL<sub>min</sub>) of −50.52 dB at a thickness of 2.20 mm, with an effective absorption bandwidth (EAB) of just 2.28 GHz. Building upon this foundation, two different periodic metamaterial structures were designed to optimize the electromagnetic absorption performance of the SiC/Al<sub>2</sub>O<sub>3</sub> composite. By employing a multi-scale design strategy, significant improvements in both RL<sub>min</sub> and EAB were achieved innovatively. The cross-shaped structure achieved efficient absorption across a frequency range of 8.20–12.40 GHz, reaching an RL<sub>min</sub> of −78.69 dB and an EAB of 3.32 GHz at a total thickness of 2.80 mm. This research provides a novel approach for designing advanced SiC-based metamaterials with excellent radar stealth performance in the X-band.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101662"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101670
Heqing Tian, Tianyu Liu, Wenguang Zhang
Molten carbonates with high operating temperatures and excellent thermal properties are very promising phase change material for high temperature thermal energy storage. However, the structure and thermal properties of carbonates at high temperatures are lacking and difficult to measure accurately. Here, a deep potential model of ternary eutectic carbonates was developed by using first-principles molecular dynamics (FPMD) simulations as an initial dataset, and active learning using Deep Potential GENerator. The results indicate that the structure of carbonates becomes loose with increasing temperature, there is rotation of the CO32- in motion, and there is a slight oscillation of the C-O bond. As the temperature increases from 700K to 1100K, the density linearly decreases from 2.01 g/cm³ to 1.86 g/cm³, and the viscosity exponentially decreases from 32.824 mPa⋅s to 3.806 mPa⋅s. The density, specific heat capacity, thermal conductivity and viscosity obtained from the simulation are in good agreement with the experimental values, where the minimum error in viscosity is only 2.45 %. This study opens a pathway to use machine learning potential to predict the melt structure and thermal properties of complex molten salt systems with high accuracy.
{"title":"High precision prediction of structure and thermal properties of ternary eutectic carbonates by machine learning potential for solar energy application","authors":"Heqing Tian, Tianyu Liu, Wenguang Zhang","doi":"10.1016/j.mtphys.2025.101670","DOIUrl":"10.1016/j.mtphys.2025.101670","url":null,"abstract":"<div><div>Molten carbonates with high operating temperatures and excellent thermal properties are very promising phase change material for high temperature thermal energy storage. However, the structure and thermal properties of carbonates at high temperatures are lacking and difficult to measure accurately. Here, a deep potential model of ternary eutectic carbonates was developed by using first-principles molecular dynamics (FPMD) simulations as an initial dataset, and active learning using Deep Potential GENerator. The results indicate that the structure of carbonates becomes loose with increasing temperature, there is rotation of the CO<sub>3</sub><sup>2-</sup> in motion, and there is a slight oscillation of the C-O bond. As the temperature increases from 700K to 1100K, the density linearly decreases from 2.01 g/cm³ to 1.86 g/cm³, and the viscosity exponentially decreases from 32.824 mPa⋅s to 3.806 mPa⋅s. The density, specific heat capacity, thermal conductivity and viscosity obtained from the simulation are in good agreement with the experimental values, where the minimum error in viscosity is only 2.45 %. This study opens a pathway to use machine learning potential to predict the melt structure and thermal properties of complex molten salt systems with high accuracy.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101670"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143191772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101652
Zihao Guan , Zhiyuan Wei , Yanyan Xue , Lulu Fu , Yang Zhao , Lu Chen , Zhipeng Huang , Mark G. Humphrey , Jun Xu , Chi Zhang
Two-dimensional (2D) Ruddlesden-Popper (RP) and Dion-Jacobson (DJ) perovskites are attractive candidates for nonlinear photonic applications, owing to their unique “multiple quantum wells” structures. However, the nonlinear optical (NLO) absorption properties of DJ perovskites with higher structural stability and charge transport capability are still not well known. Additionally, the defects at grain boundaries are a key issue limiting the optoelectronic performance of perovskite films. In this work, three n = 1 phase 2D DJ perovskite films with representative organic cations were prepared, which are (BDA)PbI4, (AMP)PbI4, and (PDMA)PbI4, respectively (BDA: 1,4-butadiammonium, AMP: 4-(aminomethyl)piperidine, PDMA: 1,4-phenylenedimethanammonium). The impact of the interlayer organic cation steric effect and conjugation effect on their NLO absorption properties was systematically explored. Subsequently, a novel poly(methyl methacrylate) (PMMA) passivation strategy was proposed that improved crystal quality and reduced perovskite ion defects. NLO absorption measurements demonstrate all pristine perovskite films manifest saturable absorption (SA) responses under femtosecond (fs) laser pulses at 515 nm and turn to reverse saturable absorption (RSA) behaviors at 800 nm. These can be attributed to the quantum and dielectric confinement effects of 2D perovskites, while the better interlayer charge transport of 2D DJ perovskites also contributes to the prominent nonlinear absorption performance. After PMMA passivation treatment, 2D DJ perovskite films exhibited significantly enhanced nonlinear absorption properties under wide-band ultrafast lasers excitation, which benefit from better crystal quality and reduced trap states, implying good universality of this strategy. Owing to the hydrophobicity of PMMA, its addition also induces better ambient stability in passivated films, improving the feasibility of this material in the practical development of photonic devices and thus having broad application prospects. This work offers new insights and a more systematic mechanism explanation for the NLO absorption properties of 2D DJ perovskite films, and presents a feasible passivation strategy for optimizing their NLO absorption performance.
{"title":"Poly(methyl methacrylate)-assisted construction for enhanced optical absorption nonlinearities in two-dimensional Dion-Jacobson perovskite films","authors":"Zihao Guan , Zhiyuan Wei , Yanyan Xue , Lulu Fu , Yang Zhao , Lu Chen , Zhipeng Huang , Mark G. Humphrey , Jun Xu , Chi Zhang","doi":"10.1016/j.mtphys.2025.101652","DOIUrl":"10.1016/j.mtphys.2025.101652","url":null,"abstract":"<div><div>Two-dimensional (2D) Ruddlesden-Popper (RP) and Dion-Jacobson (DJ) perovskites are attractive candidates for nonlinear photonic applications, owing to their unique “multiple quantum wells” structures. However, the nonlinear optical (NLO) absorption properties of DJ perovskites with higher structural stability and charge transport capability are still not well known. Additionally, the defects at grain boundaries are a key issue limiting the optoelectronic performance of perovskite films. In this work, three n = 1 phase 2D DJ perovskite films with representative organic cations were prepared, which are (BDA)PbI<sub>4</sub>, (AMP)PbI<sub>4</sub>, and (PDMA)PbI<sub>4</sub>, respectively (BDA: 1,4-butadiammonium, AMP: 4-(aminomethyl)piperidine, PDMA: 1,4-phenylenedimethanammonium). The impact of the interlayer organic cation steric effect and conjugation effect on their NLO absorption properties was systematically explored. Subsequently, a novel poly(methyl methacrylate) (PMMA) passivation strategy was proposed that improved crystal quality and reduced perovskite ion defects. NLO absorption measurements demonstrate all pristine perovskite films manifest saturable absorption (SA) responses under femtosecond (fs) laser pulses at 515 nm and turn to reverse saturable absorption (RSA) behaviors at 800 nm. These can be attributed to the quantum and dielectric confinement effects of 2D perovskites, while the better interlayer charge transport of 2D DJ perovskites also contributes to the prominent nonlinear absorption performance. After PMMA passivation treatment, 2D DJ perovskite films exhibited significantly enhanced nonlinear absorption properties under wide-band ultrafast lasers excitation, which benefit from better crystal quality and reduced trap states, implying good universality of this strategy. Owing to the hydrophobicity of PMMA, its addition also induces better ambient stability in passivated films, improving the feasibility of this material in the practical development of photonic devices and thus having broad application prospects. This work offers new insights and a more systematic mechanism explanation for the NLO absorption properties of 2D DJ perovskite films, and presents a feasible passivation strategy for optimizing their NLO absorption performance.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101652"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101654
Dongyang Wang , Ke Zhao , Tao Hong , Jiaqi Zhu , Haonan Shi , Bingchao Qin , Yongxin Qin , Guangtao Wang , Xiang Gao , Shaobo Cheng , Chongxin Shan , Li-Dong Zhao
Exploring novel material with lower thermal conductivity and excellent electrical property is beneficial to the application of thermoelectrics. The recently developed Pb3Bi2S6 is regarded as promising thermoelectric material since its intrinsically low thermal conductivity. However, the mechanism of phonon-glass behavior is unclear, and the intrinsic thermoelectric performance is relative lower. In this study, the mechanism of lower thermal conductivity and the thermoelectric transport properties are evaluated by first-principles calculations and Boltzmann transport theory. Our findings indicate that the hierarchical chemical bonding present in BiS6, PbS6, and PbS8 polyhedral structures, arising from the dual 6s2 lone pair electrons of Pb and Bi atoms, along with rattler-like behavior of Pb atoms, contributes to an intrinsically low lattice thermal conductivity in Pb3Bi2S6. Obviously multivalley in valence band edge leads to excellent electrical properties and resulting in promising thermoelectric performance under p-type doping. A maximum ZT ∼1.25 can be obtained at 700 K with carrier concentration of ∼8.07 × 1019 cm−3. This work reveals the mechanism for intrinsic low lattice thermal conductivity and provides useful guidance for achieving the promising performance in Pb3Bi2S6.
{"title":"Intrinsically low lattice thermal conductivity and multivalley band structure induced promising high thermoelectric performance in Pb3Bi2S6","authors":"Dongyang Wang , Ke Zhao , Tao Hong , Jiaqi Zhu , Haonan Shi , Bingchao Qin , Yongxin Qin , Guangtao Wang , Xiang Gao , Shaobo Cheng , Chongxin Shan , Li-Dong Zhao","doi":"10.1016/j.mtphys.2025.101654","DOIUrl":"10.1016/j.mtphys.2025.101654","url":null,"abstract":"<div><div>Exploring novel material with lower thermal conductivity and excellent electrical property is beneficial to the application of thermoelectrics. The recently developed Pb<sub>3</sub>Bi<sub>2</sub>S<sub>6</sub> is regarded as promising thermoelectric material since its intrinsically low thermal conductivity. However, the mechanism of phonon-glass behavior is unclear, and the intrinsic thermoelectric performance is relative lower. In this study, the mechanism of lower thermal conductivity and the thermoelectric transport properties are evaluated by first-principles calculations and Boltzmann transport theory. Our findings indicate that the hierarchical chemical bonding present in BiS<sub>6</sub>, PbS<sub>6</sub>, and PbS<sub>8</sub> polyhedral structures, arising from the dual 6<em>s</em><sup>2</sup> lone pair electrons of Pb and Bi atoms, along with rattler-like behavior of Pb atoms, contributes to an intrinsically low lattice thermal conductivity in Pb<sub>3</sub>Bi<sub>2</sub>S<sub>6</sub>. Obviously multivalley in valence band edge leads to excellent electrical properties and resulting in promising thermoelectric performance under <em>p</em>-type doping. A maximum <em>ZT</em> ∼1.25 can be obtained at 700 K with carrier concentration of ∼8.07 × 10<sup>19</sup> cm<sup>−3</sup>. This work reveals the mechanism for intrinsic low lattice thermal conductivity and provides useful guidance for achieving the promising performance in Pb<sub>3</sub>Bi<sub>2</sub>S<sub>6</sub>.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101654"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101657
Yongping Pu , Chunhui Wu , Fangli Yu , Xiang Lu , Yating Ning , Lei Zhang , Zenghui Liu
Lead-free dielectric ceramics, as vital components of eco-friendly advanced pulse power systems, have encountered challenges for simultaneously achieving excellent energy-storage density (Wrec) and efficiency (η) at moderate electric fields. To address this issue, a novel class of (1-x)(Na0.5Bi0.5)0.75Sr0.25TiO3-x(K0.5Ag0.5)0.97Bi0.01NbO3 (NBST-xKABN, x = 0, 0.05, 0.10 and 0.15) relaxor ferroelectric ceramics are designed and synthesized in this work. K+-Bi3+ ion pairs are introduced into NBST-xKABN ceramics to alter charge distribution and destroy local structural symmetry of A-site. Thereby, large saturation polarization is maintained, which assists in energy storage at lower electric fields and minimizing the likelihood of aging failure in energy-storage devices that operate at high electric fields. Moreover, the incorporation of KABN strengthens breakdown strength of ceramics via reducing grain size and improving density and electrical uniformity (simulated by COMSOL). Along with the enhanced relaxor behavior induced by compositional inhomogeneity and ionic disorder, NBST-0.10KABN ceramics synchronously obtain Wrec of 5.3 J/cm3 and high η of 90.0 % at a moderate electric field of 330 kV/cm. The optimum composition also exhibits satisfactory temperature (30–130 °C) and frequency (1–100 Hz) stability, accompanied by large power density (PD) of 38.2 MW/cm3 and rapid discharge rate t0.9 of 34.8 ns. This work offers an achievable tactic to develop dielectric ceramics with remarkable comprehensive energy-storage properties at moderate electric fields, so as to satisfy requirements of energy-storage capacitors in harsh circumstances.
{"title":"Synchronous realization of remarkable energy-storage density and efficiency in (Na0.5Bi0.5)0.75Sr0.25TiO3-based lead-free ceramics at moderate electric fields","authors":"Yongping Pu , Chunhui Wu , Fangli Yu , Xiang Lu , Yating Ning , Lei Zhang , Zenghui Liu","doi":"10.1016/j.mtphys.2025.101657","DOIUrl":"10.1016/j.mtphys.2025.101657","url":null,"abstract":"<div><div>Lead-free dielectric ceramics, as vital components of eco-friendly advanced pulse power systems, have encountered challenges for simultaneously achieving excellent energy-storage density (<em>W</em><sub>rec</sub>) and efficiency (<em>η</em>) at moderate electric fields. To address this issue, a novel class of (1-<em>x</em>)(Na<sub>0.5</sub>Bi<sub>0.5</sub>)<sub>0.75</sub>Sr<sub>0.25</sub>TiO<sub>3</sub>-<em>x</em>(K<sub>0.5</sub>Ag<sub>0.5</sub>)<sub>0.97</sub>Bi<sub>0.01</sub>NbO<sub>3</sub> (NBST-<em>x</em>KABN, <em>x</em> = 0, 0.05, 0.10 and 0.15) relaxor ferroelectric ceramics are designed and synthesized in this work. K<sup>+</sup>-Bi<sup>3+</sup> ion pairs are introduced into NBST-<em>x</em>KABN ceramics to alter charge distribution and destroy local structural symmetry of A-site. Thereby, large saturation polarization is maintained, which assists in energy storage at lower electric fields and minimizing the likelihood of aging failure in energy-storage devices that operate at high electric fields. Moreover, the incorporation of KABN strengthens breakdown strength of ceramics via reducing grain size and improving density and electrical uniformity (simulated by COMSOL). Along with the enhanced relaxor behavior induced by compositional inhomogeneity and ionic disorder, NBST-0.10KABN ceramics synchronously obtain <em>W</em><sub>rec</sub> of 5.3 J/cm<sup>3</sup> and high <em>η</em> of 90.0 % at a moderate electric field of 330 kV/cm. The optimum composition also exhibits satisfactory temperature (30–130 °C) and frequency (1–100 Hz) stability, accompanied by large power density (<em>P</em><sub>D</sub>) of 38.2 MW/cm<sup>3</sup> and rapid discharge rate <em>t</em><sub>0.9</sub> of 34.8 ns. This work offers an achievable tactic to develop dielectric ceramics with remarkable comprehensive energy-storage properties at moderate electric fields, so as to satisfy requirements of energy-storage capacitors in harsh circumstances.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101657"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101656
Zhiwei Chen , Xionggang Chen , Haidong Wang , Tingting Yang , Jinxia Huang , Zhiguang Guo
Conductive hydrogels with poor mechanical properties seriously limit the service life of sensors and flexible electronics. Outstanding mechanical properties and electrical conductivity are the bottleneck of the application of conductive hydrogels. To combined excellent elasticity and electronic conductivity, herein, a new method was employed to achieve elastic dissipation with low hysteresis via introduce metal ions crosslinking, thereby enhancing mechanical dissipation of polymer network. Specifically, acrylamide (AAm) is a monomer in the covalent network via free radical polymerization. Sodium alginate (SA) form metal coordination bonds with Fe3+, Zn2+ and Ca2+. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT: PSS) is selected to be a conductive polymer. The resultant AAm/SA/PEDOT: PSS (ASP) hydrogels exhibit low hysteresis, high resilience and excellent electronic conductivity. Metal coordination bonds not only provide high elasticity as elastic dissipation energy, but also enhance electrical conductivity. The ASP hydrogels display combined mechanical performances with elastic modulus (550 MPa), fracture strength (0.81 MPa), fracture strain (473 %) and work of rupture (3.13 MJ/m3), and outstanding electronic conductivity (0.32 S/cm) which has great potential for extending the service life of hydrogels.
{"title":"Metal ion mediated conductive hydrogels with low hysteresis and high resilience","authors":"Zhiwei Chen , Xionggang Chen , Haidong Wang , Tingting Yang , Jinxia Huang , Zhiguang Guo","doi":"10.1016/j.mtphys.2025.101656","DOIUrl":"10.1016/j.mtphys.2025.101656","url":null,"abstract":"<div><div>Conductive hydrogels with poor mechanical properties seriously limit the service life of sensors and flexible electronics. Outstanding mechanical properties and electrical conductivity are the bottleneck of the application of conductive hydrogels. To combined excellent elasticity and electronic conductivity, herein, a new method was employed to achieve elastic dissipation with low hysteresis via introduce metal ions crosslinking, thereby enhancing mechanical dissipation of polymer network. Specifically, acrylamide (AAm) is a monomer in the covalent network via free radical polymerization. Sodium alginate (SA) form metal coordination bonds with Fe<sup>3+</sup>, Zn<sup>2+</sup> and Ca<sup>2+</sup>. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT: PSS) is selected to be a conductive polymer. The resultant AAm/SA/PEDOT: PSS (ASP) hydrogels exhibit low hysteresis, high resilience and excellent electronic conductivity. Metal coordination bonds not only provide high elasticity as elastic dissipation energy, but also enhance electrical conductivity. The ASP hydrogels display combined mechanical performances with elastic modulus (550 MPa), fracture strength (0.81 MPa), fracture strain (473 %) and work of rupture (3.13 MJ/m<sup>3</sup>), and outstanding electronic conductivity (0.32 S/cm) which has great potential for extending the service life of hydrogels.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101656"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101664
Jacob Cook , Po-Yuan Yang , Theo Volz , Clayton Conner , Riley Satterfield , Joseph Berglund , Qiangsheng Lu , Rob G. Moore , Yueh-Ting Yao , Tay-Rong Chang , Guang Bian
High spin Chern-number insulators (HSCI) have emerged as a novel 2D topological phase of condensed matter that is beyond the classification of topological quantum chemistry. The HSCI phase with two pairs of gapless helical edge states is robust even in the presence of spin–orbit coupling due to the protection of a “hidden” feature spectrum topology. In this work, we report the observation of a semimetallic Sb monolayer carrying the same band topology as HSCI with the spin Chern number equal to 2. Our calculations further indicate a moderate lattice strain can make Sb monolayer an insulator or a semimetal with a tunable spin Chern number from 0 to 3. The results suggest strained Sb monolayers as a promising platform for exploring exotic properties of the HSCI topological matter.
{"title":"Tunable high spin Chern-number insulator phases in strained Sb monolayer","authors":"Jacob Cook , Po-Yuan Yang , Theo Volz , Clayton Conner , Riley Satterfield , Joseph Berglund , Qiangsheng Lu , Rob G. Moore , Yueh-Ting Yao , Tay-Rong Chang , Guang Bian","doi":"10.1016/j.mtphys.2025.101664","DOIUrl":"10.1016/j.mtphys.2025.101664","url":null,"abstract":"<div><div>High spin Chern-number insulators (HSCI) have emerged as a novel 2D topological phase of condensed matter that is beyond the classification of topological quantum chemistry. The HSCI phase with two pairs of gapless helical edge states is robust even in the presence of spin–orbit coupling due to the protection of a “hidden” feature spectrum topology. In this work, we report the observation of a semimetallic Sb monolayer carrying the same band topology as HSCI with the spin Chern number equal to 2. Our calculations further indicate a moderate lattice strain can make Sb monolayer an insulator or a semimetal with a tunable spin Chern number from 0 to 3. The results suggest strained Sb monolayers as a promising platform for exploring exotic properties of the HSCI topological matter.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101664"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101655
Yunbo Guo , Zhuo Wang , Siyi Bi , Qi Sun , Yinxiang Lu
Flexible electrically insulating packaging materials with high absorption performance are urgently indispensable in the wide applications for 6G electronic devices. Herein, direct modification of KH550 and low-filler loading of mSiO₂ are proposed to construct enhanced epoxy resin (EP) composite film. The resultant EP-F sample achieves an average total shielding effectiveness (SET) of 15.11 dB (0.2–2.5 THz) at a thickness of 1 mm, representing a 142 % improvement over the EP sample. At a thickness of 1.8 mm, EP-F exhibits effective THz wave absorption across 0.5–2.5 THz frequency range, with an average reflection loss (RL) value of −14 dB. The dielectric behavior and THz wave absorption of the KH550- and mSiO₂-modified EP samples were analyzed through dielectric constant spectra and Cole-Cole plots for the first time, elucidating the distinction and relationship between microwave-like polarization and infrared-like absorption mechanisms in polar dielectric polymer materials within the THz range. Moreover, the EP-F sample exhibits enhanced mechanical properties and thermal stability, with a volume resistivity of 8.75 × 1012 Ω cm and a breakdown field strength of 37.59 kV/mm. Finally, the potential application of EP-F in practical THz circuit board packaging was demonstrated through Finite difference time domain (FDTD) simulation modeling. The enhanced epoxy resin material demonstrates enormous promise for in-situ shielding and packaging of THz devices, fabrication of efficient wave-absorbing layers, and various future applications.
{"title":"Design and regulation of electromagnetic parameters of THz absorbing epoxy resin composite film for 6G electronic packaging","authors":"Yunbo Guo , Zhuo Wang , Siyi Bi , Qi Sun , Yinxiang Lu","doi":"10.1016/j.mtphys.2025.101655","DOIUrl":"10.1016/j.mtphys.2025.101655","url":null,"abstract":"<div><div>Flexible electrically insulating packaging materials with high absorption performance are urgently indispensable in the wide applications for 6G electronic devices. Herein, direct modification of KH550 and low-filler loading of mSiO₂ are proposed to construct enhanced epoxy resin (EP) composite film. The resultant EP-F sample achieves an average total shielding effectiveness (SE<sub>T</sub>) of 15.11 dB (0.2–2.5 THz) at a thickness of 1 mm, representing a 142 % improvement over the EP sample. At a thickness of 1.8 mm, EP-F exhibits effective THz wave absorption across 0.5–2.5 THz frequency range, with an average reflection loss (RL) value of −14 dB. The dielectric behavior and THz wave absorption of the KH550- and mSiO₂-modified EP samples were analyzed through dielectric constant spectra and Cole-Cole plots for the first time, elucidating the distinction and relationship between microwave-like polarization and infrared-like absorption mechanisms in polar dielectric polymer materials within the THz range. Moreover, the EP-F sample exhibits enhanced mechanical properties and thermal stability, with a volume resistivity of 8.75 × 10<sup>12</sup> Ω cm and a breakdown field strength of 37.59 kV/mm. Finally, the potential application of EP-F in practical THz circuit board packaging was demonstrated through Finite difference time domain (FDTD) simulation modeling. The enhanced epoxy resin material demonstrates enormous promise for in-situ shielding and packaging of THz devices, fabrication of efficient wave-absorbing layers, and various future applications.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101655"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.mtphys.2025.101658
Danyan Zhan , Changhui Fu , Zhengting Yu , Guangyi Tian , Yuxuan He , Xionggang Chen , Zhiguang Guo
Hygroscopic salt-hydrogel-based atmospheric water harvesting (HAWH) technology represents an auspicious approach to alleviating the water crisis, as it is not limited by factors such as climactic. Reducing hygroscopic salt leakage is of the utmost importance to maintaining the technology's consistent performance. Consequently, we have developed a composite hygroscopic material (PPy-AAC-LiCl) with in situ loaded polypyrrole (PPy) as a photothermite. The in-situ loading of PPy not only achieves the photothermal performance of PPy-AAC-LiCl but also enhances the hygroscopic performance, which is due to the presence of nitrogen atoms in the structure facilitating the formation of hydrogen bonds between water molecules, and reduces the leakage of hygroscopic salts attributed to its ability to inhibit the increase in pore size after hygroscopicity of PPy-AAC-LiCl. The experimental results show that PPy-AAC-LiCl has effective hygroscopic performance at relative humidity (RH) of 30 %–90 %. The hygroscopicity at 25 °C and RH 70 % was about 1.53 gwater gadsorbents−1 after 12 h. After ten hygroscopicity-desorption cycles, the hygroscopicity of the samples did not decrease significantly, and no white crystals appeared on the surface of the samples during the desorption process. Furthermore, PPy-AAC-LiCl demonstrated effective atmospheric water harvesting capabilities in outdoor trials, exhibiting a desorption rate of 87.6 % and a moisture absorption rate of 1.26 gwater gadsorbents−1. The preparation of this simple and environmentally friendly hygroscopic composite material lays the foundation for the future development of atmospheric water materials.
{"title":"In-situ loaded PPy hydrogel for efficient atmospheric water harvesting without any energy consumption","authors":"Danyan Zhan , Changhui Fu , Zhengting Yu , Guangyi Tian , Yuxuan He , Xionggang Chen , Zhiguang Guo","doi":"10.1016/j.mtphys.2025.101658","DOIUrl":"10.1016/j.mtphys.2025.101658","url":null,"abstract":"<div><div>Hygroscopic salt-hydrogel-based atmospheric water harvesting (HAWH) technology represents an auspicious approach to alleviating the water crisis, as it is not limited by factors such as climactic. Reducing hygroscopic salt leakage is of the utmost importance to maintaining the technology's consistent performance. Consequently, we have developed a composite hygroscopic material (PPy-AAC-LiCl) with in situ loaded polypyrrole (PPy) as a photothermite. The in-situ loading of PPy not only achieves the photothermal performance of PPy-AAC-LiCl but also enhances the hygroscopic performance, which is due to the presence of nitrogen atoms in the structure facilitating the formation of hydrogen bonds between water molecules, and reduces the leakage of hygroscopic salts attributed to its ability to inhibit the increase in pore size after hygroscopicity of PPy-AAC-LiCl. The experimental results show that PPy-AAC-LiCl has effective hygroscopic performance at relative humidity (RH) of 30 %–90 %. The hygroscopicity at 25 °C and RH 70 % was about 1.53 g<sub>water</sub> g<sub>adsorbents</sub><sup>−1</sup> after 12 h. After ten hygroscopicity-desorption cycles, the hygroscopicity of the samples did not decrease significantly, and no white crystals appeared on the surface of the samples during the desorption process. Furthermore, PPy-AAC-LiCl demonstrated effective atmospheric water harvesting capabilities in outdoor trials, exhibiting a desorption rate of 87.6 % and a moisture absorption rate of 1.26 g<sub>water</sub> g<sub>adsorbents</sub><sup>−1</sup>. The preparation of this simple and environmentally friendly hygroscopic composite material lays the foundation for the future development of atmospheric water materials.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"51 ","pages":"Article 101658"},"PeriodicalIF":10.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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