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人工晶体学报 ›› 2022, Vol. 51 ›› Issue (12): 2096-2103.

• 研究论文 • 上一篇    下一篇

Ho3+掺杂对六角YMn0.8Fe0.2O3微结构和磁性质的调控

张爱梅1, 潘茜茜1, 张大山1, 朱佳佳1, 吴小山2   

  1. 1.河海大学理学院,南京 211100;
    2.南京大学固体微结构物理国家重点实验室,南京 210093
  • 收稿日期:2022-09-04 出版日期:2022-12-15 发布日期:2023-01-09
  • 作者简介:张爱梅(1978—),女,江苏省人,博士,教授。E-mail:amzhang2009@hhu.edu.cn
  • 基金资助:
    国家自然科学基金(11404091);江苏省自然科学基金(BK20140839)

Regulation of Microstructure and Magnetic Properties of Hexagonal YMn0.8Fe0.2O3 by Doping Ho3+

ZHANG Aimei1, PAN Xixi1, ZHANG Dashan1, ZHU Jiajia1, WU Xiaoshan2   

  1. 1. College of Science, Hohai University, Nanjing 211100, China;
    2. National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
  • Received:2022-09-04 Online:2022-12-15 Published:2023-01-09

摘要: 本文利用高温固相反应法合成了六角Y1-xHoxMn0.8Fe0.2O3多晶样品,研究Ho3+掺杂对YMn0.8Fe0.2O3微结构以及磁性质的影响。X射线衍射和拉曼测量结果显示所有样品均为单相六角结构,当Ho3+掺杂浓度低于0.15时,晶格常数ac,晶胞体积及Mn—O键长均随着掺杂浓度的增加而减小。A位稀土原子位移差以及拉曼声子模式的变化表明随着Ho3+掺杂比例增加,A位稀土原子相对于平面的偏移减小,MnO5双锥体倾斜角减小,B位Mn3+的三聚作用被削弱,Mn3+—O2-—Mn3+间超交换作用减弱,反铁磁(AFM)序被抑制,反铁磁转变温度下降。磁性测量显示低温下Y0.9Ho0.1Mn0.8Fe0.2O3的磁化强度显著增强,弱铁磁(WFM)序增加,归因于Ho3+加入后系统磁阻挫行为的降低及Ho3+—O2-—Mn3+间自旋交换作用产生的铁磁序。这为进一步探索室温多铁性材料提供了思路。

关键词: 六角YMnO3, 结构畸变, MnO5双锥体, 三聚作用, 超交换作用, 磁性

Abstract: Hexagonal Y1-xHoxMn0.8Fe0.2O3 polycrystalline samples were synthesized by high-temperature solid-state reaction method. The effects of Ho3+ doping on microstructure and magnetic properties of YMn0.8Fe0.2O3 were investigated in this paper. X-ray diffraction (XRD) and Raman spectra (RS) show that all samples are of single-phase hexagonal structure without another impurity phase. When the doping concentration (x) of Ho3+ is lower than 0.15, the lattice constants, unit cell volume and bond length between the Mn—O of the samples decrease with x increasing. The decrease of the lattice constants may be related to the interaction between the Mn3+/Fe3+ 3d orbital and the Ho3+ 4f orbital, resulting in lattice distortion and electron loss. The displacements of the rare-earth atoms at the A-site relative to the plane and the inclination of the MnO5 bipyramids are suppressed with increasing doping concentration, which is demonstrated by the shift deviations of the rare-earth atoms and the variations of the Raman phonon modes. At the same time, the trimerization of Mn3+ at the B-site is weakened. The magnetic properties of the samples were measured using the superconductor quantum interference device (SQUID). Results show that the antiferromagnetic (AFM) order decreases upon Ho3+ doping, consistent with the reduced superexchange interaction between Mn3+—O2-—Mn3+. The AFM transition temperature TN decreases. Besides, the magnetization of the samples and the weak ferromagnetic (WFM) order at low temperature are significantly enhanced, which is attributed to the suppressed magnetic resistance behavior of the system and the ferromagnetic order generated by the spin exchange interaction between Ho3+—O2-—Mn3+. These provide an idea for us to further explore room temperature multiferroic materials.

Key words: hexagonal YMnO3, structural distortion, MnO5 bipyramid, trimerization, superexchange interaction, magnetic property

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