Zhibin Li, Zuhang Huang, Zheng Hu, Miaoran Deng, Ying Yin, Wenjie Mai, Jinliang Li
K metal anodes are plagued by uncontrolled dendrite growth and interfacial instability, severely limiting their practical viability. To address this, we engineer a carbon paper host with surface epoxy groups (OCP) to regulate K metal deposition. This design enables ultrafast wetting of molten K (<0.1 s) and dendrite-free plating. In situ microscopy confirms uniform K deposition on OCP, in stark contrast to the rampant dendrite formation observed on bare K. Symmetric cells achieve excellent stability, operating over 2000 h at 2 mA cm−2/0.5 mAh cm−2 and sustaining dendrite suppression up to 5 mA cm−2. Mechanistic insights demonstrate that the epoxy groups in OCP promote the formation of an inorganic-rich solid–electrolyte interphase by enhancing electron shielding and facilitating desolvation. As a result, the OCP host achieves a high average Coulombic efficiency of 99.6% over 800 cycles at 1 mA cm−2/1 mAh cm−2. When integrated with a Prussian blue analog, the full cells further exhibit almost no capacity decline after 600 cycles at 500 mA g−1. We believe that our work provides a promising strategy for suppressing dendrite growth and extending the cycle life of K metal batteries.
K金属阳极受到不受控制的枝晶生长和界面不稳定的困扰，严重限制了它们的实际可行性。为了解决这个问题，我们设计了一种带有表面环氧基团（OCP）的碳纸载体来调节K金属沉积。这种设计可以实现熔融K的超快速润湿（0.1 s）和无枝晶电镀。原位显微镜证实了OCP上均匀的K沉积，与在裸K上观察到的猖獗的树突形成形成鲜明对比。对称细胞具有出色的稳定性，在2 mA cm - 2/0.5 mAh cm - 2下工作超过2000小时，并维持高达5 mA cm - 2的树突抑制。机理分析表明，OCP中的环氧基通过增强电子屏蔽和促进脱溶，促进了富无机固体电解质界面的形成。因此，OCP主机在1 mA cm−2/1 mAh cm−2下，在800次循环中实现了99.6%的平均库仑效率。当与普鲁士蓝模拟物集成时，在500 mA g−1下进行600次循环后，完整的电池几乎没有容量下降。我们相信我们的工作为抑制枝晶生长和延长K金属电池的循环寿命提供了一个有前途的策略。
{"title":"Epoxy-driven carbon host engineering enables ultrafast wetting and dendrite-free K metal anode","authors":"Zhibin Li, Zuhang Huang, Zheng Hu, Miaoran Deng, Ying Yin, Wenjie Mai, Jinliang Li","doi":"10.1063/5.0299799","DOIUrl":"https://doi.org/10.1063/5.0299799","url":null,"abstract":"K metal anodes are plagued by uncontrolled dendrite growth and interfacial instability, severely limiting their practical viability. To address this, we engineer a carbon paper host with surface epoxy groups (OCP) to regulate K metal deposition. This design enables ultrafast wetting of molten K (&lt;0.1 s) and dendrite-free plating. In situ microscopy confirms uniform K deposition on OCP, in stark contrast to the rampant dendrite formation observed on bare K. Symmetric cells achieve excellent stability, operating over 2000 h at 2 mA cm−2/0.5 mAh cm−2 and sustaining dendrite suppression up to 5 mA cm−2. Mechanistic insights demonstrate that the epoxy groups in OCP promote the formation of an inorganic-rich solid–electrolyte interphase by enhancing electron shielding and facilitating desolvation. As a result, the OCP host achieves a high average Coulombic efficiency of 99.6% over 800 cycles at 1 mA cm−2/1 mAh cm−2. When integrated with a Prussian blue analog, the full cells further exhibit almost no capacity decline after 600 cycles at 500 mA g−1. We believe that our work provides a promising strategy for suppressing dendrite growth and extending the cycle life of K metal batteries.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"37 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microwave impedance microscopy (MIM) is a powerful technique for mapping electronic properties at the nanoscale. The current state-of-the-art, dynamic mode MIM uses lock-in detection at the probe's mechanical resonance to obtain drift-free measurements with high spatial resolution. However, this approach inherently discards valuable information encoded in the nonlinear tip–sample admittance–distance relations. Here, we introduce resonant distance spectroscopic MIM (Rz-MIM), a modality that combines wideband MIM electronics, high-speed data acquisition, and on-the-fly processing to capture complete admittance–distance spectroscopy curves at twice the mechanical resonance frequency. The resulting hyperspectral dataset encodes significantly richer information than conventional approaches and enables more quantitative determination of underlying material properties. It also enables post-processing techniques such as retrospective enhancement of spatial resolution. Our results establish Rz-MIM as a high-throughput platform for more quantitative, hyperspectral nanoelectronic imaging.
{"title":"Resonant distance spectroscopic microwave impedance microscopy","authors":"Amogh Yogesh Waghmare, Eric Y. Ma","doi":"10.1063/5.0297256","DOIUrl":"https://doi.org/10.1063/5.0297256","url":null,"abstract":"Microwave impedance microscopy (MIM) is a powerful technique for mapping electronic properties at the nanoscale. The current state-of-the-art, dynamic mode MIM uses lock-in detection at the probe's mechanical resonance to obtain drift-free measurements with high spatial resolution. However, this approach inherently discards valuable information encoded in the nonlinear tip–sample admittance–distance relations. Here, we introduce resonant distance spectroscopic MIM (Rz-MIM), a modality that combines wideband MIM electronics, high-speed data acquisition, and on-the-fly processing to capture complete admittance–distance spectroscopy curves at twice the mechanical resonance frequency. The resulting hyperspectral dataset encodes significantly richer information than conventional approaches and enables more quantitative determination of underlying material properties. It also enables post-processing techniques such as retrospective enhancement of spatial resolution. Our results establish Rz-MIM as a high-throughput platform for more quantitative, hyperspectral nanoelectronic imaging.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"226 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hindering the unpleasant bulk defects is considered an effective measure to improve the photoelectric conversion efficiency (PCE) of Cu2ZnSn(S, Se)4 (CZTSSe) thin film solar cells. In this work, rare earth La3+ ions were introduced into the Cu2ZnSn(S, Se)4 absorption layer and induced Na diffusion from the substrate, collaborating to optimize their unpleasant Sn-related and Cu-related defects. Na diffusion can reduce the CuZn defects and improve the crystallinity of CZTSSe films. The introduced La can locate at the grain boundaries of films, suppress the SnZn bulk defects, and enhance the surface potential distribution of film. Cooperation optimization helps increase the PCE of the device. With dual cation (Ag and La) doping, the PCE of the champion CZTSSe device is improved to 11.6%. Our conclusions supplement the understanding of the existence form and influence mechanism of La in kesterite materials and provide an insight into the performance optimization of kesterite devices.
{"title":"Cooperatively controlling unpleasant defects in kesterite solar cells by introducing La3+ ions induced Na diffusion","authors":"Guonan Cui, Yanchun Yang, Lulu Bai, Yanqing Liu, Zhihui Gong, Yuze Sun, Xu Wang, Junjie Bao, Shuyu Li, Chengjun Zhu","doi":"10.1063/5.0293229","DOIUrl":"https://doi.org/10.1063/5.0293229","url":null,"abstract":"Hindering the unpleasant bulk defects is considered an effective measure to improve the photoelectric conversion efficiency (PCE) of Cu2ZnSn(S, Se)4 (CZTSSe) thin film solar cells. In this work, rare earth La3+ ions were introduced into the Cu2ZnSn(S, Se)4 absorption layer and induced Na diffusion from the substrate, collaborating to optimize their unpleasant Sn-related and Cu-related defects. Na diffusion can reduce the CuZn defects and improve the crystallinity of CZTSSe films. The introduced La can locate at the grain boundaries of films, suppress the SnZn bulk defects, and enhance the surface potential distribution of film. Cooperation optimization helps increase the PCE of the device. With dual cation (Ag and La) doping, the PCE of the champion CZTSSe device is improved to 11.6%. Our conclusions supplement the understanding of the existence form and influence mechanism of La in kesterite materials and provide an insight into the performance optimization of kesterite devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"49 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wearable patches, as an advanced biosensing technology, possess significant innovative potential and market value in the realms of self-diagnosis and wearable devices. This study introduces a microchannel wearable sensing patch (MWSP) inspired by biomimetic structures that replicate the functions of plant roots, stems, veins, and leaves. This patch facilitates micro-collection, rapid enrichment, and transpiration circulation of sweat on the skin's surface, enabling accurate detection of blood glucose levels in human sweat. Experimental results demonstrate that this biomimetic MWSP exhibits a high sensitivity of 5.55 μA mM−1 cm−2 for detecting glucose concentrations. Furthermore, the anti-gravity unidirectional flow guiding membrane, which simulates leaf transpiration, effectively enhances local microcirculation of plaques and boosts evaporation efficiency by 5.83 times. This biomimetic patch presents opportunities for the advancement of wearable sensing technology.
{"title":"A biomimetic microchannel wearable sensing patch for enriching trace body fluids and promoting spatial circulation","authors":"Shuai Hu, Ziyan Liu, Qi Mao, Yifei Bai, Jie Yang, Zehao Li, Zhenwei Yang, Weixuan Jing, Zhuangde Jiang","doi":"10.1063/5.0308676","DOIUrl":"https://doi.org/10.1063/5.0308676","url":null,"abstract":"Wearable patches, as an advanced biosensing technology, possess significant innovative potential and market value in the realms of self-diagnosis and wearable devices. This study introduces a microchannel wearable sensing patch (MWSP) inspired by biomimetic structures that replicate the functions of plant roots, stems, veins, and leaves. This patch facilitates micro-collection, rapid enrichment, and transpiration circulation of sweat on the skin's surface, enabling accurate detection of blood glucose levels in human sweat. Experimental results demonstrate that this biomimetic MWSP exhibits a high sensitivity of 5.55 μA mM−1 cm−2 for detecting glucose concentrations. Furthermore, the anti-gravity unidirectional flow guiding membrane, which simulates leaf transpiration, effectively enhances local microcirculation of plaques and boosts evaporation efficiency by 5.83 times. This biomimetic patch presents opportunities for the advancement of wearable sensing technology.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"16 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tao Xu, Guibo Zheng, Junjie Jiang, Wenzhe Zhou, Zhihui Chen, Han Huang, Fangping Ouyang
Interface symmetry breaking in heterojunctions can introduce enhanced performance in optoelectronic devices, tunnel transistors, and catalytic applications. Herein, we report a solution recrystallization method for fabricating high-quality two-dimensional PbI2 nanosheets on mechanically exfoliated thin CrOCl flakes. The high crystalline quality of the synthesized heterojunctions is confirmed by a suite of characterization techniques, including atomic force microscopy and high-resolution transmission electron microscopy. Density functional theory calculations reveal the formation of a type-II band alignment at the interface, accompanied by charge transfer from the upper PbI2 layer to the underlying CrOCl. Photoluminescence (PL) and Kelvin probe force microscopy measurements confirm the interfacial charge transfer. Especially, angle-resolved polarized Raman and PL spectroscopy reveal that CrOCl induces in-plane anisotropy (IPA) in PbI2 with anisotropy ratios of 1.64 (Raman) and 1.65 (PL), which is primarily attributed to the anisotropic interfacial charge interactions. Our findings provide a platform for expanding the application prospects of isotropic PbI2 in polarization-related fields through interface induced IPA.
{"title":"In-plane optical anisotropy in PbI2 nanosheets induced by CrOCl","authors":"Tao Xu, Guibo Zheng, Junjie Jiang, Wenzhe Zhou, Zhihui Chen, Han Huang, Fangping Ouyang","doi":"10.1063/5.0300418","DOIUrl":"https://doi.org/10.1063/5.0300418","url":null,"abstract":"Interface symmetry breaking in heterojunctions can introduce enhanced performance in optoelectronic devices, tunnel transistors, and catalytic applications. Herein, we report a solution recrystallization method for fabricating high-quality two-dimensional PbI2 nanosheets on mechanically exfoliated thin CrOCl flakes. The high crystalline quality of the synthesized heterojunctions is confirmed by a suite of characterization techniques, including atomic force microscopy and high-resolution transmission electron microscopy. Density functional theory calculations reveal the formation of a type-II band alignment at the interface, accompanied by charge transfer from the upper PbI2 layer to the underlying CrOCl. Photoluminescence (PL) and Kelvin probe force microscopy measurements confirm the interfacial charge transfer. Especially, angle-resolved polarized Raman and PL spectroscopy reveal that CrOCl induces in-plane anisotropy (IPA) in PbI2 with anisotropy ratios of 1.64 (Raman) and 1.65 (PL), which is primarily attributed to the anisotropic interfacial charge interactions. Our findings provide a platform for expanding the application prospects of isotropic PbI2 in polarization-related fields through interface induced IPA.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"15 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rongxin Zhang, Lei Wang, Zixiang Zhou, Zixi Yin, Ying Liang, Meihua Chen, Gang Yu, Xin Zhang, Guijie Liang
Heavy-metal-free ZnTexSe1−x quantum dots (QDs) have attracted significant attention due to their potential to substitute Cd,Pb-based QDs for tunable emission in luminescent or display applications. In this work, a series of ZnTexSe1−x QDs capped with sequential shells including ZnSe and ZnS ranging from green to red emission are synthesized with broad Te concentration varying from x = 0.18 to 0.8. The photoluminescent properties and carrier dynamics are analyzed through combined spectral and structural characterization. The static and time-resolved photoluminescence (PL) spectra show reduced PL quantum yield and accelerated quenching kinetics owing to the synergistic effect of worse lattice mismatch and increased defects concentration at higher x values. In particular, the transient absorption (TA) spectra with regard to both single exciton and bi-exciton processes provide evidence that the energy level alignment between ZnTexSe1−x core and ZnSe shell evolves from type I to quasi-type II with increased Te concentration and leads to electron delocalization at the conduction band. Locations of the energy levels for each QD are also given in detail according to TA spectral analysis. Considering the crucial influence of the energy level structure on microscopic carrier dynamics and macroscopic optoelectronic properties, this work offers a deeper understanding of the specific carrier dynamics in ZnTexSe1−x-based QDs and supports their practical application in related optoelectronic devices.
{"title":"Te concentration-dependent carrier dynamics and electronic structure of ZnTe x Se1− x quantum dots","authors":"Rongxin Zhang, Lei Wang, Zixiang Zhou, Zixi Yin, Ying Liang, Meihua Chen, Gang Yu, Xin Zhang, Guijie Liang","doi":"10.1063/5.0308974","DOIUrl":"https://doi.org/10.1063/5.0308974","url":null,"abstract":"Heavy-metal-free ZnTexSe1−x quantum dots (QDs) have attracted significant attention due to their potential to substitute Cd,Pb-based QDs for tunable emission in luminescent or display applications. In this work, a series of ZnTexSe1−x QDs capped with sequential shells including ZnSe and ZnS ranging from green to red emission are synthesized with broad Te concentration varying from x = 0.18 to 0.8. The photoluminescent properties and carrier dynamics are analyzed through combined spectral and structural characterization. The static and time-resolved photoluminescence (PL) spectra show reduced PL quantum yield and accelerated quenching kinetics owing to the synergistic effect of worse lattice mismatch and increased defects concentration at higher x values. In particular, the transient absorption (TA) spectra with regard to both single exciton and bi-exciton processes provide evidence that the energy level alignment between ZnTexSe1−x core and ZnSe shell evolves from type I to quasi-type II with increased Te concentration and leads to electron delocalization at the conduction band. Locations of the energy levels for each QD are also given in detail according to TA spectral analysis. Considering the crucial influence of the energy level structure on microscopic carrier dynamics and macroscopic optoelectronic properties, this work offers a deeper understanding of the specific carrier dynamics in ZnTexSe1−x-based QDs and supports their practical application in related optoelectronic devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"226 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of next generation computing paradigms and memory devices relies on exploiting the unique properties of ferroelectric materials. Hafnium oxide-based ferroelectrics, which are highly compatible with semiconductor processing, offer a promising alternative to conventional perovskite ferroelectrics that face integration challenges. However, the enhancement of ferroelectricity in hafnium oxide and its dependence on epitaxial growth orientation remain insufficiently explored. In this study, we demonstrate that the epitaxial orientation of hafnium oxide is strongly correlated with the in-plane strain conditions. Depending on the strain state, the HfO2 film exhibits either (002)- or (111)-oriented epitaxial growth. Notably, the (002)-oriented films exhibit enhanced ferroelectric polarization. These findings provide an effective strategy for achieving controllable epitaxial growth of ferroelectric HfO2 and for further improving its ferroelectric performance in practical applications.
{"title":"Stress engineering in ferroelectric hafnium oxide for tuning epitaxial orientation","authors":"Li Cheng, Ziqiang Chi, Jingjing Zhang, Yanru Wu, Ruibin Zhao, Haibo Yang, Lisha Guo, Rui Su, Wenyao Zhang, Xin Zhang, Yexuan Han, Chenru Hao","doi":"10.1063/5.0292944","DOIUrl":"https://doi.org/10.1063/5.0292944","url":null,"abstract":"The development of next generation computing paradigms and memory devices relies on exploiting the unique properties of ferroelectric materials. Hafnium oxide-based ferroelectrics, which are highly compatible with semiconductor processing, offer a promising alternative to conventional perovskite ferroelectrics that face integration challenges. However, the enhancement of ferroelectricity in hafnium oxide and its dependence on epitaxial growth orientation remain insufficiently explored. In this study, we demonstrate that the epitaxial orientation of hafnium oxide is strongly correlated with the in-plane strain conditions. Depending on the strain state, the HfO2 film exhibits either (002)- or (111)-oriented epitaxial growth. Notably, the (002)-oriented films exhibit enhanced ferroelectric polarization. These findings provide an effective strategy for achieving controllable epitaxial growth of ferroelectric HfO2 and for further improving its ferroelectric performance in practical applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"148 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shen Li, Suteng Zhao, Kunlong Pan, Chen Lv, Wei Yang, Pierre Vallobra, Wei Zhang, Luding Wang, Konstantin A. Zvezdin, Xiaoyang Lin, Weisheng Zhao
The recent demonstration of single-shot ultrafast magnetization reversal in ferromagnetic spin valves—combining spin-transfer torque with optically induced ultrafast switching—has offered a promising avenue for next-generation magnetic storage technologies. However, a comprehensive theoretical framework is currently lacking to validate and elucidate the reversal mechanisms across different initial magnetic states. Here, we develop a theoretical model for optically induced ultrafast magnetization reversal by integrating the s-d exchange model with an atomistic spin dynamics approach. The proposed model's validity is corroborated through detailed comparisons with experimental time-resolved magneto-optic Kerr effect data. Our findings highlight distinct contributions from ultrafast demagnetization and ultrafast spin currents to the switching process. Furthermore, we systematically explore the influence of laser pulse parameters, such as fluence and width, as well as material-specific properties like magnetic anisotropy and Gilbert damping coefficients on ultrafast ferromagnetic reversal. Our findings indicate that increasing laser pulse fluence intensifies ultrafast demagnetization and enhances spin current strength, whereas extending pulse width delays demagnetization and diminishes spin current intensity. Notably, magnetic anisotropy exerts minimal influence on spin current generation, while higher damping coefficients amplify spin current intensity, thereby facilitating ultrafast reversal. Comparative simulations across various spin valve materials reveal that CoFe exhibits superior ultrafast spin current conversion efficiency compared to [Co/Ni]n and CoPt-based systems. This work establishes a robust theoretical framework for optically induced ultrafast magnetization reversal and provides critical insights for the design of future picosecond-scale, low-power, and nonvolatile magnetic recording devices.
{"title":"Unveiling laser-induced ultrafast switching mechanism in ferromagnetic spin valves","authors":"Shen Li, Suteng Zhao, Kunlong Pan, Chen Lv, Wei Yang, Pierre Vallobra, Wei Zhang, Luding Wang, Konstantin A. Zvezdin, Xiaoyang Lin, Weisheng Zhao","doi":"10.1063/5.0292723","DOIUrl":"https://doi.org/10.1063/5.0292723","url":null,"abstract":"The recent demonstration of single-shot ultrafast magnetization reversal in ferromagnetic spin valves—combining spin-transfer torque with optically induced ultrafast switching—has offered a promising avenue for next-generation magnetic storage technologies. However, a comprehensive theoretical framework is currently lacking to validate and elucidate the reversal mechanisms across different initial magnetic states. Here, we develop a theoretical model for optically induced ultrafast magnetization reversal by integrating the s-d exchange model with an atomistic spin dynamics approach. The proposed model's validity is corroborated through detailed comparisons with experimental time-resolved magneto-optic Kerr effect data. Our findings highlight distinct contributions from ultrafast demagnetization and ultrafast spin currents to the switching process. Furthermore, we systematically explore the influence of laser pulse parameters, such as fluence and width, as well as material-specific properties like magnetic anisotropy and Gilbert damping coefficients on ultrafast ferromagnetic reversal. Our findings indicate that increasing laser pulse fluence intensifies ultrafast demagnetization and enhances spin current strength, whereas extending pulse width delays demagnetization and diminishes spin current intensity. Notably, magnetic anisotropy exerts minimal influence on spin current generation, while higher damping coefficients amplify spin current intensity, thereby facilitating ultrafast reversal. Comparative simulations across various spin valve materials reveal that CoFe exhibits superior ultrafast spin current conversion efficiency compared to [Co/Ni]n and CoPt-based systems. This work establishes a robust theoretical framework for optically induced ultrafast magnetization reversal and provides critical insights for the design of future picosecond-scale, low-power, and nonvolatile magnetic recording devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"144 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Yi Huang, Zheng Duan Zhang, Zhe Guo, Shu Ya Wu, Xiao Qiang Liu, Xiang Ming Chen
Oxygen octahedral rotation is essential for hybrid improper ferroelectrics (HIFs), but interlayer rumpling will compete with oxygen octahedron rotation, leading to the suppression of ferroelectricity in layered perovskite materials containing trivalent cations at the B-site. In the present work, single-phase dense La2Sr(Sc1−xInx)2O7 ceramics with double-layered Ruddlesden–Popper structures have been prepared, and the presence of room-temperature HIF is evidenced by the ferroelectric hysteresis loops. The polar A21am phase is adopted at room temperature, and it will transform into a nonpolar Amam phase above the Curie temperature. The Curie temperature increases linearly with the content of In3+ cation and with decreasing tolerance factor, whereas the ferroelectric polarization decreases with the substitution of In3+ cation at the B-site owing to the suppression of oxygen octahedral rotation. The present work demonstrates the room-temperature HIF in La2Sr(Sc1–xInx)2O7 ceramics and emphasizes the essential role of tolerance factor in determining the Curie temperature.
{"title":"Hybrid improper ferroelectricity and phase transition in La2Sr(Sc1− x In x )2O7 ceramics","authors":"Wei Yi Huang, Zheng Duan Zhang, Zhe Guo, Shu Ya Wu, Xiao Qiang Liu, Xiang Ming Chen","doi":"10.1063/5.0292857","DOIUrl":"https://doi.org/10.1063/5.0292857","url":null,"abstract":"Oxygen octahedral rotation is essential for hybrid improper ferroelectrics (HIFs), but interlayer rumpling will compete with oxygen octahedron rotation, leading to the suppression of ferroelectricity in layered perovskite materials containing trivalent cations at the B-site. In the present work, single-phase dense La2Sr(Sc1−xInx)2O7 ceramics with double-layered Ruddlesden–Popper structures have been prepared, and the presence of room-temperature HIF is evidenced by the ferroelectric hysteresis loops. The polar A21am phase is adopted at room temperature, and it will transform into a nonpolar Amam phase above the Curie temperature. The Curie temperature increases linearly with the content of In3+ cation and with decreasing tolerance factor, whereas the ferroelectric polarization decreases with the substitution of In3+ cation at the B-site owing to the suppression of oxygen octahedral rotation. The present work demonstrates the room-temperature HIF in La2Sr(Sc1–xInx)2O7 ceramics and emphasizes the essential role of tolerance factor in determining the Curie temperature.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"6 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yan Zhou, Jian Wang, Shanshan An, Zeyi Zhao, Yanbin Guo, Aiqi Yang, Xianjie Pu
Extreme wind events are increasing due to environmental degradation, often causing power outages and safety risks. To enable reliable sensing under such conditions, a gradient-segmented flag triboelectric nanogenerator is developed for omnidirectional wind sensing and self-powered warning. The polyethylene terephthalate-based flag with gradient thickness provides tunable stiffness and mass distribution, optimizing response range and sensitivity. A cantilever beam model elucidates the segment-dependent dynamics. The single-segment device achieves ∼500 nC charge output and 215 mW/m2 power density at 6.5 m/s, powering 434 LEDs, while the three-segment design enables accurate wind speed detection from 2 to 7 m/s. A hybrid system integrating both modes and a wind direction–adaptive structure ensures omnidirectional performance. This work demonstrates a robust, self-sustained solution for wind sensing and warning, capable of operating during power failures and supporting disaster risk mitigation.
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