Pub Date : 2025-09-18DOI: 10.1016/j.jssc.2025.125675
Rihab Trimech , Khalifa Souiwa , Bo Song , Zhanhua Wei , Mourad Hidouri , Brahim Ayed , Ruqin Ma , Yong Yang , Gregorio F. Ortiz
Medium-entropy phosphate cathode materials with an α-CrPO4-type structure exhibit promising potential for Na-ion insertion. Fe-substituted Na2-uNi2+2-xNi3+x(Cr3+1-yCr4+y)1-wFe3+w(PO4)3 (where u = x + y and w = 0, 0.5, and 1) were synthesized via a modified Pechini method. Rietveld refinement of the X-ray diffraction patterns confirmed the stoichiometries Na1.7Ni2+1.9Ni3+0.1Cr3+0.8Cr4+0.2(PO4)3, Na1.6Ni2+1.7Ni3+0.3Cr3+0.4Cr4+0.1Fe3+0.5(PO4)3 and Na1.8Ni2+1.8Ni3+0.2Fe3+(PO4)3. Although structurally similar to the α-Na2Ni2Fe(PO4)3, these materials display distinct atomic site coordinates and occupancies, with transition metals M(1) and M(2) (M = Fe, Ni, Cr) statistically disordered across 4a and 8g sites. Electrochemical performance was evaluated within a moderate voltage range of 1.00–3.75 V vs. Na+/Na. Due to the initially low sodium content, with partial occupation of 4b sites and empty 4c sites, the first discharge cycle yielded specific capacities of 165.8, 188.9, and 205.34 mA h g−1, with reversibility rates of 80.1, 84.1, and 90 %, respectively. Ex-situ X-ray diffraction patterns, X-ray photoelectron spectroscopy, and Cr and Ni–K edge X-ray absorption near edge structure analyses confirmed the occurrence of Na-ion insertion reactions, ruling out conversion reaction. The materials demonstrated reversible multi-electron reactions involving moderate activation of Cr4+/Cr3+/Cr2+, Fe3+/Fe2+/Fe0, and Ni3+/Ni2+/Ni0 redox couples while preserving the structure. Ultimately, Fe substitution effectively suppressed phase transitions and enhanced structural reversibility.
α- crpo4型结构的中熵磷酸盐正极材料具有良好的na离子插入潜力。采用改进的Pechini法合成了fe取代的Na2-uNi2+2-xNi3+x(Cr3+1- ycr4 +y)1- wfe3 +w(PO4)3（其中u = x +y, w = 0,0.5, 1）。x射线衍射图的Rietveld细化证实了Na1.7Ni2+1.9Ni3+0.1Cr3+0.8Cr4+0.2(PO4)3、Na1.6Ni2+1.7Ni3+0.3Cr3+0.4Cr4+0.1Fe3+0.5(PO4)3和Na1.8Ni2+1.8Ni3+0.2 fe3 +(PO4)3的化学计量。虽然结构类似于α-Na2Ni2Fe(PO4)3，但这些材料显示出不同的原子位置坐标和占位，过渡金属M(1)和M(2) （M = Fe, Ni, Cr）在4a和8g位点上统计上无序。在1.00-3.75 V vs. Na+/Na的中等电压范围内评价了电化学性能。由于初始钠含量较低，4b位点和4c位点部分被占据，第一次放电循环的比容量分别为165.8、188.9和205.34 mA h g−1，可逆性分别为80.1、84.1和90%。非原位x射线衍射图、x射线光电子能谱以及Cr和Ni-K边缘x射线吸收近边结构分析证实了na离子插入反应的发生，排除了转化反应的可能。材料表现出可逆的多电子反应，在保持结构的同时适度激活Cr4+/Cr3+/Cr2+、Fe3+/Fe2+/Fe0和Ni3+/Ni2+/Ni0氧化还原对。最终，铁取代有效地抑制了相变，增强了结构的可逆性。
{"title":"Structural and spectroscopic insights of medium-entropy Na2-uNi2+2-xNi3+x(Cr3+1-yCr4+y)1-wFe3+w(PO4)3 cathodes with sodium-ion insertion","authors":"Rihab Trimech , Khalifa Souiwa , Bo Song , Zhanhua Wei , Mourad Hidouri , Brahim Ayed , Ruqin Ma , Yong Yang , Gregorio F. Ortiz","doi":"10.1016/j.jssc.2025.125675","DOIUrl":"10.1016/j.jssc.2025.125675","url":null,"abstract":"<div><div>Medium-entropy phosphate cathode materials with an α-CrPO<sub>4</sub>-type structure exhibit promising potential for Na-ion insertion. Fe-substituted Na<sub>2-u</sub>Ni<sup>2+</sup><sub>2-x</sub>Ni<sup>3+</sup><sub>x</sub>(Cr<sup>3+</sup><sub>1-y</sub>Cr<sup>4+</sup><sub>y</sub>)<sub>1-w</sub>Fe<sup>3+</sup><sub>w</sub>(PO<sub>4</sub>)<sub>3</sub> (where u = x + y and w = 0, 0.5, and 1) were synthesized via a modified Pechini method. Rietveld refinement of the X-ray diffraction patterns confirmed the stoichiometries Na<sub>1.7</sub>Ni<sup>2+</sup><sub>1.9</sub>Ni<sup>3+</sup><sub>0.1</sub>Cr<sup>3+</sup><sub>0.8</sub>Cr<sup>4+</sup><sub>0.2</sub>(PO<sub>4</sub>)<sub>3</sub>, Na<sub>1.6</sub>Ni<sup>2+</sup><sub>1.7</sub>Ni<sup>3+</sup><sub>0.3</sub>Cr<sup>3+</sup><sub>0.4</sub>Cr<sup>4+</sup><sub>0.1</sub>Fe<sup>3+</sup><sub>0.5</sub>(PO<sub>4</sub>)<sub>3</sub> and Na<sub>1.8</sub>Ni<sup>2+</sup><sub>1.8</sub>Ni<sup>3+</sup><sub>0.2</sub>Fe<sup>3+</sup>(PO<sub>4</sub>)<sub>3</sub>. Although structurally similar to the α-Na<sub>2</sub>Ni<sub>2</sub>Fe(PO<sub>4</sub>)<sub>3</sub>, these materials display distinct atomic site coordinates and occupancies, with transition metals M(1) and M(2) (M = Fe, Ni, Cr) statistically disordered across 4a and 8g sites. Electrochemical performance was evaluated within a moderate voltage range of 1.00–3.75 V vs. Na<sup>+</sup>/Na. Due to the initially low sodium content, with partial occupation of 4b sites and empty 4c sites, the first discharge cycle yielded specific capacities of 165.8, 188.9, and 205.34 mA h g<sup>−1</sup>, with reversibility rates of 80.1, 84.1, and 90 %, respectively. Ex-situ X-ray diffraction patterns, X-ray photoelectron spectroscopy, and Cr and Ni–K edge X-ray absorption near edge structure analyses confirmed the occurrence of Na-ion insertion reactions, ruling out conversion reaction. The materials demonstrated reversible multi-electron reactions involving moderate activation of Cr<sup>4+</sup>/Cr<sup>3+</sup>/Cr<sup>2+</sup>, Fe<sup>3+</sup>/Fe<sup>2+</sup>/Fe<sup>0</sup>, and Ni<sup>3+</sup>/Ni<sup>2+</sup>/Ni<sup>0</sup> redox couples while preserving the structure. Ultimately, Fe substitution effectively suppressed phase transitions and enhanced structural reversibility.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125675"},"PeriodicalIF":3.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-17DOI: 10.1016/j.jssc.2025.125603
Andrei Novitskii , Cédric Bourgès , Krushna Kumari Raut , Jean-François Halet , Takao Mori
We report a rare-earth–free multi-filling strategy to enhance the thermoelectric performance of Co4Sb12 skutterudites. Co-filling with In and Ga, along with partial Sb for Te substitution induces beneficial compositing effect, refines grain size, and tunes filler's solubility. An optimal In:Ga ratio, achieved in In0.3Ga0.1Co4Sb11.8Te0.2, maximizes dodecahedral site occupancy and yields a high power factor (≈ 40 μWcm−1 K−2) in the 300−600 K range, reaching values close to that of rare-earth–filled skutterudites.
{"title":"Synergistic In and Ga Co-filling with Sb substitution in Co4Sb12 skutterudites: A beneficial compositing effect for high power factor","authors":"Andrei Novitskii , Cédric Bourgès , Krushna Kumari Raut , Jean-François Halet , Takao Mori","doi":"10.1016/j.jssc.2025.125603","DOIUrl":"10.1016/j.jssc.2025.125603","url":null,"abstract":"<div><div>We report a rare-earth–free multi-filling strategy to enhance the thermoelectric performance of Co<sub>4</sub>Sb<sub>12</sub> skutterudites. Co-filling with In and Ga, along with partial Sb for Te substitution induces beneficial compositing effect, refines grain size, and tunes filler's solubility. An optimal In:Ga ratio, achieved in In<sub>0.3</sub>Ga<sub>0.1</sub>Co<sub>4</sub>Sb<sub>11.8</sub>Te<sub>0.2</sub>, maximizes dodecahedral site occupancy and yields a high power factor (≈ 40 μWcm<sup>−1</sup> K<sup>−2</sup>) in the 300−600 K range, reaching values close to that of rare-earth–filled skutterudites.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125603"},"PeriodicalIF":3.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-17DOI: 10.1016/j.jssc.2025.125642
Jiumei Chu , Xianglong Ren , Xue Yang , Mengyu Lin , Dianquan Dong
This paper describes the successful construction of a fluorine-doped titanium series cesium ion sieve precursor (CTO-F) with an optimized surface coordination structure. This was achieved by introducing a trace amount of fluorine into the TiO2 lattice using a modified solvothermal method with regulation control fluoride ion doping. The precursor was then acid-modified to produce fluorine-doped protonated titanate (HTO-F). The addition of fluorine ions was found to significantly enhance the cesium ion trapping ability of the titanium-based cesium ion sieve. The materials CTO-F and HTO-F were characterized post-synthesis via XRD, SEM, EDS, FT-IR, Raman spectroscopy, XPS, BET and TG-DTG to evaluate their structural and compositional properties. This demonstrated that trace fluoride ion doping did not alter the original layered structure of Cs2Ti6O13. A series of adsorption experiments were performed to evaluate the influence of solution pH, initial Cs+ concentration, and contact time on the adsorption performance of the ion-exchange sieves. Additionally, this paper investigates and discusses the effects of dilute hydrochloric acid concentration on the acid modification of CTO-F, the selectivity of HTO-F for cesium ion in mixed-ion and single-ion solutions, and the stability of HTO-F's adsorption capacity during cyclic experiments. The experimental study showed that HTO-F, after being modified with 0.4 M dilute hydrochloric acid, could reach a saturation adsorption capacity of 373.16 mg/g under optimal conditions of 298 K, pH = 12, and an initial cesium ion concentration of 3000 mg/L. HTO-F exhibited high selectivity and adsorption capacity for Cs+ after five adsorption-desorption cycles. After five cycles, its adsorption capacity for Cs+ was still 82.7 % of the initial capacity, demonstrating its good cyclic stability.
{"title":"Preparation and adsorption performance of anion-doped titanium-based cesium ion sieves","authors":"Jiumei Chu , Xianglong Ren , Xue Yang , Mengyu Lin , Dianquan Dong","doi":"10.1016/j.jssc.2025.125642","DOIUrl":"10.1016/j.jssc.2025.125642","url":null,"abstract":"<div><div>This paper describes the successful construction of a fluorine-doped titanium series cesium ion sieve precursor (CTO-F) with an optimized surface coordination structure. This was achieved by introducing a trace amount of fluorine into the TiO<sub>2</sub> lattice using a modified solvothermal method with regulation control fluoride ion doping. The precursor was then acid-modified to produce fluorine-doped protonated titanate (HTO-F). The addition of fluorine ions was found to significantly enhance the cesium ion trapping ability of the titanium-based cesium ion sieve. The materials CTO-F and HTO-F were characterized post-synthesis via XRD, SEM, EDS, FT-IR, Raman spectroscopy, XPS, BET and TG-DTG to evaluate their structural and compositional properties. This demonstrated that trace fluoride ion doping did not alter the original layered structure of Cs<sub>2</sub>Ti<sub>6</sub>O<sub>13</sub>. A series of adsorption experiments were performed to evaluate the influence of solution pH, initial Cs<sup>+</sup> concentration, and contact time on the adsorption performance of the ion-exchange sieves. Additionally, this paper investigates and discusses the effects of dilute hydrochloric acid concentration on the acid modification of CTO-F, the selectivity of HTO-F for cesium ion in mixed-ion and single-ion solutions, and the stability of HTO-F's adsorption capacity during cyclic experiments. The experimental study showed that HTO-F, after being modified with 0.4 M dilute hydrochloric acid, could reach a saturation adsorption capacity of 373.16 mg/g under optimal conditions of 298 K, pH = 12, and an initial cesium ion concentration of 3000 mg/L. HTO-F exhibited high selectivity and adsorption capacity for Cs<sup>+</sup> after five adsorption-desorption cycles. After five cycles, its adsorption capacity for Cs<sup>+</sup> was still 82.7 % of the initial capacity, demonstrating its good cyclic stability.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125642"},"PeriodicalIF":3.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-16DOI: 10.1016/j.jssc.2025.125674
Yifei Pan , Ruizhen Zhang , Aojing Deng , Kai Zong
Amine-free synthesis of low silica ZSM-5 with high crystallinity and good morphology is challenging. In this paper, high-crystalline ZSM-5 with a fed silica-alumina ratio (SAR) of 25 was successfully synthesized via interzeolite transformation of NaA with the assistance of sodium sulfate (Na2SO4), and the structures, morphologies, and microporous properties of the products were characterized by XRPD, SEM, FT-IR, N2 adsorption-desorption and so on. Firstly, low-silica ZSM-5 was synthesized at 180 and 190 °C for 48 h in the absence of sodium sulfate to find an appropriate process parameter. Then, Na2SO4 was introduced into the synthetic sol and the effects of Na2SO4 contents (Na2SO4/SiO2 = 0.05–0.35) on the crystallization of ZSM-5 were investigated. Thirdly, the crystallization kinetics of low-silica ZSM-5 were comparatively studied with and without the assistance of sodium sulfate, at the same time, the synthesis of low-silica ZSM-5 assisted with NaF was also investigated to explore the role of anion. The results showed that the maximum crystallinity of low-silica ZSM-5 was only 78 % at the condition of 180 °C and an alkali-silica ratio of 0.1; the introduction of Na2SO4 greatly accelerated the nucleation and growth of ZSM-5 and the relative crystallinity of the product reached a high level of 108 % when the Na2SO4/SiO2 ratio was 0.25, mainly attributed to the introduction of more Na+ as cationic nucleation sites, meanwhile, SO42− anions also played an important role in accelerating nucleation of ZSM-5 due to its Hofmeister effect and salting-out effect, all the above served as a driving force for the rapid assembly of MFI skeleton via interzeolite transformation of NaA, greatly reduced the nucleation activation energy of low-silica ZSM-5, finally high-crystalline products were obtained at relatively low alkalinity. Unlike NaF, the larger size of the products obtained via sodium sulfate than via NaF may be attributed to the introduction of weakly alkaline NaF promoting the depolymerization of NaA and thus the improvement of nucleation rate of ZSM-5 to some extent.
{"title":"Sodium salt-assisted transcrystal synthesis of low-silica ZSM-5 in the amine-free system with the investigation of mechanism","authors":"Yifei Pan , Ruizhen Zhang , Aojing Deng , Kai Zong","doi":"10.1016/j.jssc.2025.125674","DOIUrl":"10.1016/j.jssc.2025.125674","url":null,"abstract":"<div><div>Amine-free synthesis of low silica ZSM-5 with high crystallinity and good morphology is challenging. In this paper, high-crystalline ZSM-5 with a fed silica-alumina ratio (SAR) of 25 was successfully synthesized via interzeolite transformation of NaA with the assistance of sodium sulfate (Na<sub>2</sub>SO<sub>4</sub>), and the structures, morphologies, and microporous properties of the products were characterized by XRPD, SEM, FT-IR, N<sub>2</sub> adsorption-desorption and so on. Firstly, low-silica ZSM-5 was synthesized at 180 and 190 °C for 48 h in the absence of sodium sulfate to find an appropriate process parameter. Then, Na<sub>2</sub>SO<sub>4</sub> was introduced into the synthetic sol and the effects of Na<sub>2</sub>SO<sub>4</sub> contents (Na<sub>2</sub>SO<sub>4</sub>/SiO<sub>2</sub> = 0.05–0.35) on the crystallization of ZSM-5 were investigated. Thirdly, the crystallization kinetics of low-silica ZSM-5 were comparatively studied with and without the assistance of sodium sulfate, at the same time, the synthesis of low-silica ZSM-5 assisted with NaF was also investigated to explore the role of anion. The results showed that the maximum crystallinity of low-silica ZSM-5 was only 78 % at the condition of 180 °C and an alkali-silica ratio of 0.1; the introduction of Na<sub>2</sub>SO<sub>4</sub> greatly accelerated the nucleation and growth of ZSM-5 and the relative crystallinity of the product reached a high level of 108 % when the Na<sub>2</sub>SO<sub>4</sub>/SiO<sub>2</sub> ratio was 0.25, mainly attributed to the introduction of more Na<sup>+</sup> as cationic nucleation sites, meanwhile, SO<sub>4</sub><sup>2−</sup> anions also played an important role in accelerating nucleation of ZSM-5 due to its Hofmeister effect and salting-out effect, all the above served as a driving force for the rapid assembly of MFI skeleton via interzeolite transformation of NaA, greatly reduced the nucleation activation energy of low-silica ZSM-5, finally high-crystalline products were obtained at relatively low alkalinity. Unlike NaF, the larger size of the products obtained via sodium sulfate than via NaF may be attributed to the introduction of weakly alkaline NaF promoting the depolymerization of NaA and thus the improvement of nucleation rate of ZSM-5 to some extent.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125674"},"PeriodicalIF":3.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nonlinear optical (NLO) materials with strong second-harmonic effect have important applications in the field of lasers. In this work, NLO crystal PbBi3PO8 was designed by introducing Pb2+ and Bi3+ ions with lone pair electrons and stereochemical activity into phosphate system, and was grown using high-temperature melting method. Yellow transparent crystal with the dimensions of 5 × 5 × 2 mm3 was obtained, and the structure, thermal and optical properties were studied. The results indicate that PbBi3PO8 crystal has highly disorder three-dimensional structure, formed by connecting Pb–O, Bi–O polyhedra and [PO4] tetrahedra through common points or edges. The phosphate crystal shows wide transmission range of 381–5185 nm with the bandgap of 3.14 eV. Powder frequency doubling test shows that PbBi3PO8 crystal has large nonlinear optical response (2.3 × KDP), which can be credited to the synergistic effect of multiple Pb–O and Bi–O polyhedral polarizations and the consistent orientation of [PO4] functional groups in the structure. This study provides a design method to improve the nonlinear performance of materials.
{"title":"Growth, structure and optical properties of PbBi3PO8 crystals","authors":"Huatong Jiang, Jianfu Zhao, Chao Li, Shengxuan Yang, Dongxiao Cai, Hechun Jiang, Xiulan Duan, Fapeng Yu","doi":"10.1016/j.jssc.2025.125672","DOIUrl":"10.1016/j.jssc.2025.125672","url":null,"abstract":"<div><div>Nonlinear optical (NLO) materials with strong second-harmonic effect have important applications in the field of lasers. In this work, NLO crystal PbBi<sub>3</sub>PO<sub>8</sub> was designed by introducing Pb<sup>2+</sup> and Bi<sup>3+</sup> ions with lone pair electrons and stereochemical activity into phosphate system, and was grown using high-temperature melting method. Yellow transparent crystal with the dimensions of 5 × 5 × 2 mm<sup>3</sup> was obtained, and the structure, thermal and optical properties were studied. The results indicate that PbBi<sub>3</sub>PO<sub>8</sub> crystal has highly disorder three-dimensional structure, formed by connecting Pb–O, Bi–O polyhedra and [PO<sub>4</sub>] tetrahedra through common points or edges. The phosphate crystal shows wide transmission range of 381–5185 nm with the bandgap of 3.14 eV. Powder frequency doubling test shows that PbBi<sub>3</sub>PO<sub>8</sub> crystal has large nonlinear optical response (2.3 × KDP), which can be credited to the synergistic effect of multiple Pb–O and Bi–O polyhedral polarizations and the consistent orientation of [PO<sub>4</sub>] functional groups in the structure. This study provides a design method to improve the nonlinear performance of materials.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125672"},"PeriodicalIF":3.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-15DOI: 10.1016/j.jssc.2025.125670
Luke R. Sadergaski , Don D. Dick , Jason R. Darvin , Eliel Villa-Aleman , David Abrecht , Lucas Sweet
Investigating alpha-decay induced aging in PuO2 is useful in nuclear forensics; helping to determine the time since last calcination. This was previously investigate by monitoring the damage to 240PuO2 over the course of a few years. The rate of alpha-decay induced aging has long been assumed to scale only with the decay rate of other isotopes without direct verification. This article reports the first alpha-decay aging study of 238PuO2 by Raman spectroscopy. Contrary to the expected 10 days for 238PuO2 to reach steady state based on 240PuO2 studies, the alpha aging curve reached an approximate steady state ∼24–30 h after laser annealing. While the cause of the order of magnitude decrease is unknown, it is speculated that dynamic annealing could contribute to the differences in rate of induced aging. The Raman spectra of annealed and aged 238PuO2 matched the expected features in 239PuO2 and 240PuO2 spectra; showing no formation of new stable chemical species in the material such as secondary Pu oxide phases (e.g., Pu4O9). Results indicate that 238Pu could be leveraged for rapid alpha-decay aging studies to characterize alpha-decay induced features and better understand matrix temperatures and the annealing of Frankel pair defects.
{"title":"Investigating rapid alpha-decay induced aging of 238PuO2 by Raman Spectroscopy","authors":"Luke R. Sadergaski , Don D. Dick , Jason R. Darvin , Eliel Villa-Aleman , David Abrecht , Lucas Sweet","doi":"10.1016/j.jssc.2025.125670","DOIUrl":"10.1016/j.jssc.2025.125670","url":null,"abstract":"<div><div>Investigating alpha-decay induced aging in PuO<sub>2</sub> is useful in nuclear forensics; helping to determine the time since last calcination. This was previously investigate by monitoring the damage to <sup>240</sup>PuO<sub>2</sub> over the course of a few years. The rate of alpha-decay induced aging has long been assumed to scale only with the decay rate of other isotopes without direct verification. This article reports the first alpha-decay aging study of <sup>238</sup>PuO<sub>2</sub> by Raman spectroscopy. Contrary to the expected 10 days for <sup>238</sup>PuO<sub>2</sub> to reach steady state based on <sup>240</sup>PuO<sub>2</sub> studies, the alpha aging curve reached an approximate steady state ∼24–30 h after laser annealing. While the cause of the order of magnitude decrease is unknown, it is speculated that dynamic annealing could contribute to the differences in rate of induced aging. The Raman spectra of annealed and aged <sup>238</sup>PuO<sub>2</sub> matched the expected features in <sup>239</sup>PuO<sub>2</sub> and <sup>240</sup>PuO<sub>2</sub> spectra; showing no formation of new stable chemical species in the material such as secondary Pu oxide phases (e.g., Pu<sub>4</sub>O<sub>9</sub>). Results indicate that <sup>238</sup>Pu could be leveraged for rapid alpha-decay aging studies to characterize alpha-decay induced features and better understand matrix temperatures and the annealing of Frankel pair defects.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125670"},"PeriodicalIF":3.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study resolves the ambiguity regarding the suitability of equimolar and non-equimolar high-entropy ferroelectrics (HEFs) for diverse industrial applications. HEFs show great promise as lead-free ceramic materials for improving pulse power device efficiency, enhancing energy density, and boosting overall performance. HEF ceramics, specifically [(Na (0.5) K0.5)0.5(Bi0.5Eu0.5)0.5] (1-x) SrxTiO3 (x = 0.2, 0.3, 0.4), are synthesized using a solid-state technique with both equimolar and non-equimolar compositions. Structural analysis confirms their single-phase perovskite cubic structure, further supported by tolerance factor calculations. Surface morphology analysis reveals well-packed grains with minimal porosity, while strontium (Sr) promotes grain growth, resulting in larger grain sizes with increasing Sr content. A maximum dielectric constant of ∼1855 was observed at 1 kHz, exhibiting frequency dispersion at x = 0.3. The highest recoverable energy storage density (ESD) achieves 0.68 J/cm3 at x = 0.2 in an electric field of 122.5 kV/cm, with an efficiency of 40 %. Equimolar compositions demonstrate superior energy storage performance due to higher configurational entropy. For Sr0.2, scaling analysis reveals three distinct regions, with the recoverable energy density (Wrec) increasing alongside the employed electric field, highlighting the material's energy storage potential. Additionally, the maximum power density (Pdmax) is calculated as 10 MW/cm3 for Sr0.2. This study underscores the advantages of equimolar HEF compositions in tuning dielectric and ferroelectric properties for advanced energy storage applications.
{"title":"Compositional engineering of A-site high-entropy ferroelectrics using equimolar and non-equimolar methods","authors":"Ranjan Kumar Sahu, Gudla Surendra kumar, Saket Asthana","doi":"10.1016/j.jssc.2025.125671","DOIUrl":"10.1016/j.jssc.2025.125671","url":null,"abstract":"<div><div>This study resolves the ambiguity regarding the suitability of equimolar and non-equimolar high-entropy ferroelectrics (HEFs) for diverse industrial applications. HEFs show great promise as lead-free ceramic materials for improving pulse power device efficiency, enhancing energy density, and boosting overall performance. HEF ceramics, specifically [(Na <sub>(0.5)</sub> K<sub>0.5</sub>)<sub>0.5</sub>(Bi<sub>0.5</sub>Eu<sub>0.5</sub>)<sub>0.5</sub>] <sub>(1-x)</sub> Sr<sub>x</sub>TiO<sub>3</sub> (x = 0.2, 0.3, 0.4), are synthesized using a solid-state technique with both equimolar and non-equimolar compositions. Structural analysis confirms their single-phase perovskite cubic structure, further supported by tolerance factor calculations. Surface morphology analysis reveals well-packed grains with minimal porosity, while strontium (Sr) promotes grain growth, resulting in larger grain sizes with increasing Sr content. A maximum dielectric constant of ∼1855 was observed at 1 kHz, exhibiting frequency dispersion at x = 0.3. The highest recoverable energy storage density (ESD) achieves 0.68 J/cm<sup>3</sup> at x = 0.2 in an electric field of 122.5 kV/cm, with an efficiency of 40 %. Equimolar compositions demonstrate superior energy storage performance due to higher configurational entropy. For Sr0.2, scaling analysis reveals three distinct regions, with the recoverable energy density (W<sub>rec</sub>) increasing alongside the employed electric field, highlighting the material's energy storage potential. Additionally, the maximum power density (P<sub>dmax</sub>) is calculated as 10 MW/cm<sup>3</sup> for Sr0.2. This study underscores the advantages of equimolar HEF compositions in tuning dielectric and ferroelectric properties for advanced energy storage applications.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125671"},"PeriodicalIF":3.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Direct visualization of the spatial distribution of oxygen redox activity in single (primary) particles of Li-rich layered oxide (LLO) is essential for a deeper understanding of its reaction mechanism. In this study, we propose a real-space mapping approach for identifying oxygen redox-active domains using scanning transmission electron microscopy (STEM)-based electron energy-loss spectroscopy (EELS). Electron-released oxygen (oxidized oxygen) was clearly detected by EELS and soft X-ray absorption spectroscopy (S-XAS) in the charged state of Li1+x(Ni0.3Mn0.7)1-xO2 (0 < x < 1/3). STEM-EELS spectrum imaging clarified that the fluctuations in oxygen redox activity closely correlate with the Ni distribution within LLO particles, found that oxidized oxygen species distribution was well correlated with Ni-poor region. The heterogeneous distribution of transition metals leads to non-uniform activation of oxygen in the particles, with Ni-rich domains suppressing oxygen redox activity. This real-space mapping of oxygen activity domains at the LLO single-particle level contributes to understanding the material's mechanism.
直接可视化富锂层状氧化物（LLO）单个（初级）颗粒中氧氧化还原活性的空间分布对于更深入地理解其反应机制至关重要。在这项研究中，我们提出了一种基于扫描透射电子显微镜（STEM）的电子能量损失谱（EELS）的实时空间映射方法来识别氧氧化还原活性域。在Li1+x(Ni0.3Mn0.7)1-xO2 （0 < x < 1/3）带电状态下，用EELS和软x射线吸收光谱（S-XAS）清晰地检测到电子释放氧（氧化氧）。tem - eels光谱成像明确了氧氧化还原活性的波动与LLO颗粒内Ni的分布密切相关，发现氧化氧的种类分布与Ni贫区有很好的相关性。过渡金属的不均匀分布导致颗粒中氧的不均匀活化，富镍结构域抑制氧氧化还原活性。这种在LLO单粒子水平上的氧活性域的真实空间映射有助于理解材料的机制。
{"title":"Nanoscale mapping of spatial fluctuations in oxygen redox activity within a charged single particle of Li-rich layered oxide","authors":"Mitsunori Kitta , Mitsuharu Tabuchi , Daisuke Asakura , Toyoki Okumura , Satoshi Uchida","doi":"10.1016/j.jssc.2025.125667","DOIUrl":"10.1016/j.jssc.2025.125667","url":null,"abstract":"<div><div>Direct visualization of the spatial distribution of oxygen redox activity in single (primary) particles of Li-rich layered oxide (LLO) is essential for a deeper understanding of its reaction mechanism. In this study, we propose a real-space mapping approach for identifying oxygen redox-active domains using scanning transmission electron microscopy (STEM)-based electron energy-loss spectroscopy (EELS). Electron-released oxygen (oxidized oxygen) was clearly detected by EELS and soft X-ray absorption spectroscopy (S-XAS) in the charged state of Li<sub>1+<em>x</em></sub>(Ni<sub>0.3</sub>Mn<sub>0.7</sub>)<sub>1-<em>x</em></sub>O<sub>2</sub> (0 < <em>x</em> < 1/3). STEM-EELS spectrum imaging clarified that the fluctuations in oxygen redox activity closely correlate with the Ni distribution within LLO particles, found that oxidized oxygen species distribution was well correlated with Ni-poor region. The heterogeneous distribution of transition metals leads to non-uniform activation of oxygen in the particles, with Ni-rich domains suppressing oxygen redox activity. This real-space mapping of oxygen activity domains at the LLO single-particle level contributes to understanding the material's mechanism.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125667"},"PeriodicalIF":3.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-15DOI: 10.1016/j.jssc.2025.125666
L.A. Benitez-Alarcon , A.C. García-Velasco , L. Zamora-Peredo , J. Hernández-Torres , A. Báez-Rodríguez , C. Falcony , J. Guzmán-Mendoza
Homogeneous and optimized nanostructured ZnO films were successfully synthesized by a simple technique. The growth conditions were modified from the change in synthesis temperature; from 300 to 450 °C, leading to significant modifications in ZnO morphology, luminescent properties and thicknesses of ZnO films. These structural and optical properties changes allowed emissions at different wavelengths. The color of emissions from ZnO films are according to defect levels of ZnO nanostructures. Photoluminescent results and CIE chromaticity analysis demonstrated three different emission bands: yellow-orange, green and cyan due to high concentration of Zni-VZn and CB-VO transitions. This proposed synthesis suggests its integration into scalable fabrication process for obtain nanostructured ZnO films for luminescent devices.
{"title":"Defect-driven color emissions in nanostructured ZnO films synthesized by two-step ultrasonic spray pyrolysis","authors":"L.A. Benitez-Alarcon , A.C. García-Velasco , L. Zamora-Peredo , J. Hernández-Torres , A. Báez-Rodríguez , C. Falcony , J. Guzmán-Mendoza","doi":"10.1016/j.jssc.2025.125666","DOIUrl":"10.1016/j.jssc.2025.125666","url":null,"abstract":"<div><div>Homogeneous and optimized nanostructured ZnO films were successfully synthesized by a simple technique. The growth conditions were modified from the change in synthesis temperature; from 300 to 450 °C, leading to significant modifications in ZnO morphology, luminescent properties and thicknesses of ZnO films. These structural and optical properties changes allowed emissions at different wavelengths. The color of emissions from ZnO films are according to defect levels of ZnO nanostructures. Photoluminescent results and CIE chromaticity analysis demonstrated three different emission bands: yellow-orange, green and cyan due to high concentration of Z<sub>ni</sub>-V<sub>Zn</sub> and CB-V<sub>O</sub> transitions. This proposed synthesis suggests its integration into scalable fabrication process for obtain nanostructured ZnO films for luminescent devices.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125666"},"PeriodicalIF":3.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-14DOI: 10.1016/j.jssc.2025.125668
Jiale Zhang , Sophie F. Fletcher , Wen Liang Tan , Frederick P. Marlton , Brendan J. Kennedy
The structure of Cs2AgBiBr6 between 80 and 350 K was determined by Rietveld refinement of high-resolution synchrotron X-ray diffraction data. At room temperature, the material adopts a cubic Fmm structure with rock-salt-like ordering of Ag+ and Bi3+ cations, doubling the perovskite unit cell. Despite the lower valence Ag+ being larger than Bi3+ (1.15 vs 1.03 Å), the Ag–Br bond is slightly shorter than the Bi–Br bond (2.8103(8) vs 2.8229(8) Å), with nearly equal MO6 octahedral volumes, suggesting greater covalency and distortion in AgBr6 units. The Cs+ cations are underbonded in the cubic phase and large anisotropic Br displacements perpendicular to Ag–Br–Bi chains, attributed to dynamic rotations of corner-sharing octahedra, partially offsetting this underbonding. Below 120 K, the Br displacements freeze, inducing a continuous transition to a tetragonal I4/m structure. An unusual expansion in the volume of the BiBr6 polyhedara occurs in the low temperature tetragonal phase. The structural changes with temperature reflect the balance between ionic size, bonding character, and dynamic lattice effects.
采用高分辨率同步加速器x射线衍射数据的Rietveld细化，确定了Cs2AgBiBr6在80 ~ 350 K之间的结构。在室温下，材料采用立方f3m形式，以岩盐形式排列Ag+和Bi3+阳离子，使钙钛矿单元电池加倍。尽管价态较低的Ag+比Bi3+大（1.15 vs 1.03 Å）， Ag - br键比Bi-Br键略短(2.8103（8)vs 2.8229(8) Å）， MO6八面体体积几乎相等，表明AgBr6单元的共价和畸变更大。Cs+阳离子在立方相中存在欠键，而垂直于Ag-Br-Bi链的大的各向异性Br位移，归因于共享角八面体的动态旋转，部分抵消了这种欠键。当温度低于120k时，Br的位移冻结，导致其连续转变为I4/m的四边形结构。在低温四方相中，BiBr6多面体的体积出现了不寻常的膨胀。结构随温度的变化反映了离子大小、成键特性和动态晶格效应之间的平衡。
{"title":"Structural studies of Cs2AgBiBr6 double perovskite","authors":"Jiale Zhang , Sophie F. Fletcher , Wen Liang Tan , Frederick P. Marlton , Brendan J. Kennedy","doi":"10.1016/j.jssc.2025.125668","DOIUrl":"10.1016/j.jssc.2025.125668","url":null,"abstract":"<div><div>The structure of Cs<sub>2</sub>AgBiBr<sub>6</sub> between 80 and 350 K was determined by Rietveld refinement of high-resolution synchrotron X-ray diffraction data. At room temperature, the material adopts a cubic <em>Fm</em> <span><math><mrow><mover><mn>3</mn><mo>‾</mo></mover></mrow></math></span><em>m</em> structure with rock-salt-like ordering of Ag<sup>+</sup> and Bi<sup>3+</sup> cations, doubling the perovskite unit cell. Despite the lower valence Ag<sup>+</sup> being larger than Bi<sup>3+</sup> (1.15 vs 1.03 Å), the Ag–Br bond is slightly shorter than the Bi–Br bond (2.8103(8) vs 2.8229(8) Å), with nearly equal <em>M</em>O<sub>6</sub> octahedral volumes, suggesting greater covalency and distortion in AgBr<sub>6</sub> units. The Cs<sup>+</sup> cations are underbonded in the cubic phase and large anisotropic Br displacements perpendicular to Ag–Br–Bi chains, attributed to dynamic rotations of corner-sharing octahedra, partially offsetting this underbonding. Below 120 K, the Br displacements freeze, inducing a continuous transition to a tetragonal <em>I</em>4/<em>m</em> structure. An unusual expansion in the volume of the BiBr<sub>6</sub> polyhedara occurs in the low temperature tetragonal phase. The structural changes with temperature reflect the balance between ionic size, bonding character, and dynamic lattice effects.</div></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":"353 ","pages":"Article 125668"},"PeriodicalIF":3.5,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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