无机材料学报 ›› 2020, Vol. 35 ›› Issue (8): 895-901.DOI: 10.15541/jim20190606

所属专题: 功能材料论文精选(一):光学材料(2020)

• 研究论文 • 上一篇    下一篇

Zn3-xMnxTeO6的晶体结构与吸收光谱和磁性研究

李淑芳(),赵爽,周潇,李满荣()   

  1. 中山大学 化学学院, 生物无机和合成化学教育部重点实验室, 广州 510275
  • 收稿日期:2019-11-29 修回日期:2020-01-16 出版日期:2020-08-20 网络出版日期:2020-03-06
  • 作者简介:李淑芳(1989–), 女, 博士. E-mail: lishufang@mail.sysu.edu.cn
    LI Shufang(1989–), female, PhD. E-mail: lishu-fang@mail.sysu.edu.cn
  • 基金资助:
    国家自然科学基金(21801253);国家自然科学基金(21875287);广东省“珠江人才计划”引进创新团队项目(2017ZT07C069)

Crystal Structures, Optical, and Magnetic Properties of Zn3-xMnxTeO6

LI Shufang(),ZHAO Shuang,ZHOU Xiao,LI Manrong()   

  1. Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
  • Received:2019-11-29 Revised:2020-01-16 Published:2020-08-20 Online:2020-03-06
  • Supported by:
    National Natural Science Foundation of China(21801253);National Natural Science Foundation of China(21875287);Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2017ZT07C069)

摘要:

本工作主要研究Mn 2+离子掺杂的类刚玉系氧化物Zn3TeO6(0<x≤2.0)的晶体结构与光学性质和磁性的变化。Zn3-xMnxTeO6粉末样品通过固相反应合成。Mn掺杂量的相图表明, x<1.0时保持单斜(C2/c)结构, 1.0≤x≤1.6为单斜(C2/c)和三方六面体混合相(R-3), x≥1.8时完全转变为R-3相, 且x=2.0时形成ZnMn2TeO6, Te-O和Mn/Zn-O键长增大, 八面体发生更大畸变。X射线粉末衍射结构精修也表明R-3相中Zn/MnO6为畸变八面体。随着Mn 2+掺杂含量的增加, Zn3-xMnxTeO6系列化合物不仅结构发生变化, 其颜色也由浅变深。紫外吸收光谱中随着掺杂浓度的增加, 400~550 nm处的吸收增强, 样品的光学带隙也由3.25 eV (x=0.1)逐渐减小到2.08 eV (x=2.0), 分析表明, 可见区吸收的增强是源于MnO6八面体中Zn/MnO6八面体中Mn 2+离子的d-d跃迁, 导致样品由浅黄色逐渐变为暗黄色。 磁性测试表明, 固溶体的反铁磁转变温度随着Mn 2+掺杂量的提高而逐渐增加, 且掺入的Mn 2+离子以高自旋态 存在。

关键词: Zn3TeO6-Mn3TeO6, 晶体结构, 磁性, 紫外吸收光谱

Abstract:

The effects of Mn 2+ doping on the structural, optical and magnetic properties of the corundum-related oxide Zn3TeO6 were investigated. Polycrystalline ceramic samples of the solid solution Zn3-xMnxTeO6 (0<x≤2.0) were prepared by a solid-state reaction route. Phase diagram as a function of Mn concentration indicates monoclinic (C2/c) structure for x<1.0, disproportionated mixing of both monoclinic (C2/c) and rhombohedral (R-3) structure for 1.0≤x≤1.6, and R-3 structure for x≥1.8. Moreover, when x=2.0, ZnMn2TeO6 was formed, in which the bond length of Te-O and Mn/Zn-O increased, and the Mn/ZnO6 octahedra became more distorted. Rietveld refinements of the crystal structures from the powder X-ray diffraction (XRD) data showed that the Zn/MnO6 octahedra were highly distorted in R-3 phase. With the increase of Mn 2+ doping content, the solid solution Zn3-xMnxTeO6 demonstrated not only the structure change from C2/c to R-3, but also the color evolution from light yellow to dark yellow. In optical absorption spectroscopy, with the increase of Mn 2+ doping concentration, the absorption at 400-550 nm was enhanced, and the optical band gap of the samples gradually decreased from 3.25 eV (x=0.1) to 2.08 eV (x=2.0). Analysis revealed that the color of samples changed from light yellow to dark yellow is due to the d-d transition of Mn 2+ ions in Zn/MnO6 octahedron. Magnetic measurements indicate that the antiferromagnetic transition temperature of the solid solution gradually increased with the increase of the doping amount of Mn 2+, and the doped Mn 2+ ions exist in a high spin state.

Key words: Zn3TeO6-Mn3TeO6, crystal structure, magnetism, ultraviolet absorption spectrum

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