Avnee Chauhan , Andreas Frickel , Kousik Papakollu , Sabine Begand , Mathias Herrmann , Enrico Bernardo , Dušan Galusek
{"title":"放电等离子烧结法制备CeO2-δ·(Dy,La,Sm,Y)2O3高熵氧化物的相变与相稳定性","authors":"Avnee Chauhan , Andreas Frickel , Kousik Papakollu , Sabine Begand , Mathias Herrmann , Enrico Bernardo , Dušan Galusek","doi":"10.1016/j.jeurceramsoc.2025.117552","DOIUrl":null,"url":null,"abstract":"<div><div>The influence of spark plasma sintering (SPS) on the phase stability and bandgap of single-phase HEO ceramics with the composition CeO<sub>2-δ</sub>·(Dy,La,Sm,Y)<sub>2</sub>O<sub>3</sub> was studied. Single phase HEO powders were prepared by combustion synthesis. The powders were consolidated by SPS at temperatures 1300° C, 1400° C, and 1600° C to prepare dense bulk ceramics. At 1600° C, a complete cubic-to-monoclinic phase transformation occurred, driven by Ce<sup>4 +</sup> to Ce<sup>3+</sup> reduction under reducing SPS conditions. The change in the oxidation state of Ce resulted in an increase of the average ionic radius driving the cubic-to-monoclinic phase transition. Annealing the monoclinic samples at 1200° C in air led to a reversible transformation to the cubic structure. The phase transformations coupled with the presence of oxygen vacancies resulted in a bandgap energy reduction.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 14","pages":"Article 117552"},"PeriodicalIF":5.8000,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Polymorphic transitions and phase stability of CeO2-δ·(Dy,La,Sm,Y)2O3 high-entropy oxides consolidated by spark plasma sintering\",\"authors\":\"Avnee Chauhan , Andreas Frickel , Kousik Papakollu , Sabine Begand , Mathias Herrmann , Enrico Bernardo , Dušan Galusek\",\"doi\":\"10.1016/j.jeurceramsoc.2025.117552\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The influence of spark plasma sintering (SPS) on the phase stability and bandgap of single-phase HEO ceramics with the composition CeO<sub>2-δ</sub>·(Dy,La,Sm,Y)<sub>2</sub>O<sub>3</sub> was studied. Single phase HEO powders were prepared by combustion synthesis. The powders were consolidated by SPS at temperatures 1300° C, 1400° C, and 1600° C to prepare dense bulk ceramics. At 1600° C, a complete cubic-to-monoclinic phase transformation occurred, driven by Ce<sup>4 +</sup> to Ce<sup>3+</sup> reduction under reducing SPS conditions. The change in the oxidation state of Ce resulted in an increase of the average ionic radius driving the cubic-to-monoclinic phase transition. Annealing the monoclinic samples at 1200° C in air led to a reversible transformation to the cubic structure. The phase transformations coupled with the presence of oxygen vacancies resulted in a bandgap energy reduction.</div></div>\",\"PeriodicalId\":17408,\"journal\":{\"name\":\"Journal of The European Ceramic Society\",\"volume\":\"45 14\",\"pages\":\"Article 117552\"},\"PeriodicalIF\":5.8000,\"publicationDate\":\"2025-05-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of The European Ceramic Society\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0955221925003723\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, CERAMICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The European Ceramic Society","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0955221925003723","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
Polymorphic transitions and phase stability of CeO2-δ·(Dy,La,Sm,Y)2O3 high-entropy oxides consolidated by spark plasma sintering
The influence of spark plasma sintering (SPS) on the phase stability and bandgap of single-phase HEO ceramics with the composition CeO2-δ·(Dy,La,Sm,Y)2O3 was studied. Single phase HEO powders were prepared by combustion synthesis. The powders were consolidated by SPS at temperatures 1300° C, 1400° C, and 1600° C to prepare dense bulk ceramics. At 1600° C, a complete cubic-to-monoclinic phase transformation occurred, driven by Ce4 + to Ce3+ reduction under reducing SPS conditions. The change in the oxidation state of Ce resulted in an increase of the average ionic radius driving the cubic-to-monoclinic phase transition. Annealing the monoclinic samples at 1200° C in air led to a reversible transformation to the cubic structure. The phase transformations coupled with the presence of oxygen vacancies resulted in a bandgap energy reduction.
期刊介绍:
The Journal of the European Ceramic Society publishes the results of original research and reviews relating to ceramic materials. Papers of either an experimental or theoretical character will be welcomed on a fully international basis. The emphasis is on novel generic science concerning the relationships between processing, microstructure and properties of polycrystalline ceramics consolidated at high temperature. Papers may relate to any of the conventional categories of ceramic: structural, functional, traditional or composite. The central objective is to sustain a high standard of research quality by means of appropriate reviewing procedures.