Elizabeth Sobalvarro Converse , Gabriella King , Jun Li , M.A. Subramanian
{"title":"新型介质Te6+焦绿石:ABiMTeO7-y (A = Cd, Ca)M = Cr, Ga, Sc, In, Fe)","authors":"Elizabeth Sobalvarro Converse , Gabriella King , Jun Li , M.A. Subramanian","doi":"10.1016/j.progsolidstchem.2022.100378","DOIUrl":null,"url":null,"abstract":"<div><p><span>Bond valence sum analysis is a powerful tool used in evaluating and validating crystal structures; especially when those structures are complex in nature. The pyrochlore structure type is versatile in not only the unique bonding that it exhibits, but also in the properties that results from the structure. This paper aims to center the discussion of evaluating the pyrochlore structure using the bond valence sum method. In this study, novel quaternary pyrochlores with a general stoichiometry of </span><em>A</em>Bi<em>M</em>TeO<sub>7</sub> (<em>A</em> = Cd, Ca; <em>M</em><span> = Cr, Ga, Sc, In, Fe) were synthesized and characterized for their structural, magnetic, and dielectric properties. Two representative compounds within this series of pyrochlores, BiCaFeTeO</span><sub>7</sub> and BiCdFeTeO<sub>7</sub><span>, were structurally characterized utilizing a combination of high-resolution synchrotron X-ray diffraction and neutron diffraction revealing oxygen deficient pyrochlore systems which were off from the expected stoichiometry with respect to the </span><em>M</em> site. The <em>A</em> site of both pyrochlores were found to be moved off-center from the expected 16<em>d</em> site to the 96<em>h</em><span> displaced position at a magnitude of 0.25 Å and 0.22 Å for the Bi/Ca and Bi/Cd systems, respectively. These structures were evaluated using the bond valence sum method and compared with trends in the literature. The properties are also reported for the Bi/Ca system for the first time, showing relatively high dielectric constants with a low dielectric loss which are primarily independent of frequency and temperature. The magnetic measurements for the Bi/Ca system for the magnetic substitutions reveal a paramagnet and antiferromagnetic properties for the Fe and Cr analogs, respectively. The novel BiCa</span><em>M</em>TeO<sub>7</sub> quaternary pyrochlore system shows great promise as an emerging dielectric material.</p></div>","PeriodicalId":415,"journal":{"name":"Progress in Solid State Chemistry","volume":null,"pages":null},"PeriodicalIF":9.1000,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Bond valence sum analysis of pyrochlore oxides including the novel dielectric Te6+ pyrochlores: ABiMTeO7-y (A = Cd, Ca; M = Cr, Ga, Sc, In, Fe)\",\"authors\":\"Elizabeth Sobalvarro Converse , Gabriella King , Jun Li , M.A. Subramanian\",\"doi\":\"10.1016/j.progsolidstchem.2022.100378\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><span>Bond valence sum analysis is a powerful tool used in evaluating and validating crystal structures; especially when those structures are complex in nature. The pyrochlore structure type is versatile in not only the unique bonding that it exhibits, but also in the properties that results from the structure. This paper aims to center the discussion of evaluating the pyrochlore structure using the bond valence sum method. In this study, novel quaternary pyrochlores with a general stoichiometry of </span><em>A</em>Bi<em>M</em>TeO<sub>7</sub> (<em>A</em> = Cd, Ca; <em>M</em><span> = Cr, Ga, Sc, In, Fe) were synthesized and characterized for their structural, magnetic, and dielectric properties. Two representative compounds within this series of pyrochlores, BiCaFeTeO</span><sub>7</sub> and BiCdFeTeO<sub>7</sub><span>, were structurally characterized utilizing a combination of high-resolution synchrotron X-ray diffraction and neutron diffraction revealing oxygen deficient pyrochlore systems which were off from the expected stoichiometry with respect to the </span><em>M</em> site. The <em>A</em> site of both pyrochlores were found to be moved off-center from the expected 16<em>d</em> site to the 96<em>h</em><span> displaced position at a magnitude of 0.25 Å and 0.22 Å for the Bi/Ca and Bi/Cd systems, respectively. These structures were evaluated using the bond valence sum method and compared with trends in the literature. The properties are also reported for the Bi/Ca system for the first time, showing relatively high dielectric constants with a low dielectric loss which are primarily independent of frequency and temperature. The magnetic measurements for the Bi/Ca system for the magnetic substitutions reveal a paramagnet and antiferromagnetic properties for the Fe and Cr analogs, respectively. The novel BiCa</span><em>M</em>TeO<sub>7</sub> quaternary pyrochlore system shows great promise as an emerging dielectric material.</p></div>\",\"PeriodicalId\":415,\"journal\":{\"name\":\"Progress in Solid State Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":9.1000,\"publicationDate\":\"2022-12-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Progress in Solid State Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0079678622000322\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Progress in Solid State Chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0079678622000322","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
摘要
键价和分析是评价和验证晶体结构的有力工具;尤其是当这些结构本质上很复杂的时候。焦绿石结构类型是通用的,不仅在其独特的键,而且在其结构的结果性质。本文主要讨论了用键价和法评价焦绿石结构的方法。在本研究中,具有ABiMTeO7 (a = Cd, Ca;合成了M = Cr, Ga, Sc, In, Fe),并对其结构,磁性和介电性能进行了表征。利用高分辨率同步x射线衍射和中子衍射的结合,对该系列中两个具有代表性的化合物BiCaFeTeO7和BiCdFeTeO7进行了结构表征,揭示了与M位点的化学计量学不同的缺氧焦绿石系统。在Bi/Ca和Bi/Cd体系中,两种焦绿石的A位点从预期的16d位置偏移到96h位置,其偏移幅度分别为0.25 Å和0.22 Å。用键价和法对这些结构进行了评价,并与文献趋势进行了比较。Bi/Ca体系的性质也首次被报道,表现出相对较高的介电常数和较低的介电损耗,主要不受频率和温度的影响。磁取代的Bi/Ca体系的磁测量结果显示,Fe和Cr类似物分别具有顺磁性和反铁磁性。新型BiCaMTeO7季焦氯化物体系作为一种新兴的介电材料,具有广阔的应用前景。
Bond valence sum analysis of pyrochlore oxides including the novel dielectric Te6+ pyrochlores: ABiMTeO7-y (A = Cd, Ca; M = Cr, Ga, Sc, In, Fe)
Bond valence sum analysis is a powerful tool used in evaluating and validating crystal structures; especially when those structures are complex in nature. The pyrochlore structure type is versatile in not only the unique bonding that it exhibits, but also in the properties that results from the structure. This paper aims to center the discussion of evaluating the pyrochlore structure using the bond valence sum method. In this study, novel quaternary pyrochlores with a general stoichiometry of ABiMTeO7 (A = Cd, Ca; M = Cr, Ga, Sc, In, Fe) were synthesized and characterized for their structural, magnetic, and dielectric properties. Two representative compounds within this series of pyrochlores, BiCaFeTeO7 and BiCdFeTeO7, were structurally characterized utilizing a combination of high-resolution synchrotron X-ray diffraction and neutron diffraction revealing oxygen deficient pyrochlore systems which were off from the expected stoichiometry with respect to the M site. The A site of both pyrochlores were found to be moved off-center from the expected 16d site to the 96h displaced position at a magnitude of 0.25 Å and 0.22 Å for the Bi/Ca and Bi/Cd systems, respectively. These structures were evaluated using the bond valence sum method and compared with trends in the literature. The properties are also reported for the Bi/Ca system for the first time, showing relatively high dielectric constants with a low dielectric loss which are primarily independent of frequency and temperature. The magnetic measurements for the Bi/Ca system for the magnetic substitutions reveal a paramagnet and antiferromagnetic properties for the Fe and Cr analogs, respectively. The novel BiCaMTeO7 quaternary pyrochlore system shows great promise as an emerging dielectric material.
期刊介绍:
Progress in Solid State Chemistry offers critical reviews and specialized articles written by leading experts in the field, providing a comprehensive view of solid-state chemistry. It addresses the challenge of dispersed literature by offering up-to-date assessments of research progress and recent developments. Emphasis is placed on the relationship between physical properties and structural chemistry, particularly imperfections like vacancies and dislocations. The reviews published in Progress in Solid State Chemistry emphasize critical evaluation of the field, along with indications of current problems and future directions. Papers are not intended to be bibliographic in nature but rather to inform a broad range of readers in an inherently multidisciplinary field by providing expert treatises oriented both towards specialists in different areas of the solid state and towards nonspecialists. The authorship is international, and the subject matter will be of interest to chemists, materials scientists, physicists, metallurgists, crystallographers, ceramists, and engineers interested in the solid state.