{"title":"电流诱导的二氧化钛结构和电子变化","authors":"","doi":"10.1016/j.mtphys.2024.101546","DOIUrl":null,"url":null,"abstract":"<div><p>In-situ diffuse neutron scattering experiments revealed that when electric current is passed through single crystals of rutile TiO<sub>2</sub> under conditions conducive to flash sintering, it induces the formation of parallel planes of oxygen vacancies. Specifically, a current perpendicular to the <em>c</em>-axis generates planes normal to the (132) reciprocal lattice vector, whereas currents aligned with the <em>c</em>-axis form planes normal to the (132) and to the (225) vector. The concentration of defects increases with incresing current. The structural modifications are linked to the appearance of signatures of interacting Ti<sup>3+</sup> moments in magnetic susceptibility, signifying a structural collapse around the vacancy planes. Electrical conductivity measurements of the modified material reveal several electronic transitions between semiconducting states (via a metal-like intermediate state) with the smallest gap being 27 meV. Pristine TiO<sub>2</sub> can be restored by heating followed by slow cooling in air. Our work suggests a novel paradigm for achieving switching of electrical conductivity related to the flash phenomenon.</p></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":null,"pages":null},"PeriodicalIF":10.0000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Structural and electronic transformations in TiO2 induced by electric current\",\"authors\":\"\",\"doi\":\"10.1016/j.mtphys.2024.101546\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In-situ diffuse neutron scattering experiments revealed that when electric current is passed through single crystals of rutile TiO<sub>2</sub> under conditions conducive to flash sintering, it induces the formation of parallel planes of oxygen vacancies. Specifically, a current perpendicular to the <em>c</em>-axis generates planes normal to the (132) reciprocal lattice vector, whereas currents aligned with the <em>c</em>-axis form planes normal to the (132) and to the (225) vector. The concentration of defects increases with incresing current. The structural modifications are linked to the appearance of signatures of interacting Ti<sup>3+</sup> moments in magnetic susceptibility, signifying a structural collapse around the vacancy planes. Electrical conductivity measurements of the modified material reveal several electronic transitions between semiconducting states (via a metal-like intermediate state) with the smallest gap being 27 meV. Pristine TiO<sub>2</sub> can be restored by heating followed by slow cooling in air. Our work suggests a novel paradigm for achieving switching of electrical conductivity related to the flash phenomenon.</p></div>\",\"PeriodicalId\":18253,\"journal\":{\"name\":\"Materials Today Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":10.0000,\"publicationDate\":\"2024-09-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials Today Physics\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2542529324002220\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Today Physics","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2542529324002220","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
原位弥散中子散射实验表明,在有利于闪烁烧结的条件下,当电流通过金红石二氧化钛单晶体时,会诱导氧空位平行平面的形成。具体来说,垂直于 c 轴的电流会产生与(132)倒易点阵矢量法线平行的平面,而与 c 轴对齐的电流则会形成与(132)和(225)矢量法线平行的平面。缺陷的浓度随着电流的增大而增加。结构的改变与磁感应强度中出现的相互作用 Ti3+ 矩的特征有关,这标志着空缺平面周围的结构坍塌。对改性材料的电导率测量显示了半导体态(通过类金属中间态)之间的若干电子跃迁,最小间隙为 27 meV。通过在空气中加热并缓慢冷却,可以恢复原始二氧化钛。我们的工作为实现与闪烁现象有关的导电性切换提供了一种新的范例。
Structural and electronic transformations in TiO2 induced by electric current
In-situ diffuse neutron scattering experiments revealed that when electric current is passed through single crystals of rutile TiO2 under conditions conducive to flash sintering, it induces the formation of parallel planes of oxygen vacancies. Specifically, a current perpendicular to the c-axis generates planes normal to the (132) reciprocal lattice vector, whereas currents aligned with the c-axis form planes normal to the (132) and to the (225) vector. The concentration of defects increases with incresing current. The structural modifications are linked to the appearance of signatures of interacting Ti3+ moments in magnetic susceptibility, signifying a structural collapse around the vacancy planes. Electrical conductivity measurements of the modified material reveal several electronic transitions between semiconducting states (via a metal-like intermediate state) with the smallest gap being 27 meV. Pristine TiO2 can be restored by heating followed by slow cooling in air. Our work suggests a novel paradigm for achieving switching of electrical conductivity related to the flash phenomenon.
期刊介绍:
Materials Today Physics is a multi-disciplinary journal focused on the physics of materials, encompassing both the physical properties and materials synthesis. Operating at the interface of physics and materials science, this journal covers one of the largest and most dynamic fields within physical science. The forefront research in materials physics is driving advancements in new materials, uncovering new physics, and fostering novel applications at an unprecedented pace.