Jahn–Taller distortion on exchange interactions between cations in MnxCu1−xCo2O4 system
Jahn–Taller distortion on exchange interactions between cations in MnxCu1−xCo2O4 system
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Jahn–MnxCu1–xCo2O4 体系中阳离子之间交换相互作用的更高畸变
DOI：
10.1088/1361-6463/ac89fe
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Denglu Hou
中科院分区：
文献类型：
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作者：
Lei Xu;Congmian Zhen;Zizhou Shui;Dayin Xu;Lu Liu;Li Ma;Dewei Zhao;Denglu Hou
采用低温固相反应法制备了纯相MnxCu 1− xCo 2 O 4（x= 0，0.25，0.5，0.75，1）多晶粉末。随着Mn离子掺杂到八面体位置，晶胞由立方相转变为四面体相，八面体Co 3+离子向四面体位置迁移，成为高自旋Co2+离子。当Mn掺杂浓度较低时，样品主要由四面体Cu 2+之间的反铁磁（AFM）相互作用控制。随着Mn含量的增加，四面体Co2+和八面体Mn 3+之间出现亚铁磁相互作用.当Mn浓度足够高时，由于强的Jahn-Taller畸变，Mn的e g能级分裂，这减弱了四面体阳离子与八面体阳离子之间的相互作用，并且增强了八面体阳离子之间的相互作用。八面体Mn 3+之间的铁磁相互作用和八面体Mn 2+之间的AFM相互作用变得明显.随着Mn含量的增加，磁有序温度从20 K提高到93 K，最大交换偏置场为1.063 kOe。
Pure-phase Mn x Cu 1− x Co 2 O 4 (x= 0, 0.25, 0.5, 0.75 and 1) polycrystalline powders were prepared by using a low-temperature solid-phase reaction method. With doping Mn ion into the octahedral sites, the unit cell transforms from cubic phase to tetragonal phase, and the octahedral Co 3+ ions move to the tetrahedral sites and become high spin Co 2+ ions. When the doped Mn concentration is low, the sample is dominated by antiferromagnetic (AFM) interactions between tetrahedral Cu 2+. As the Mn concentration increases, ferrimagnetic interactions between tetrahedral Co 2+ and octahedral Mn 3+ can be observed. When the Mn concentration is high enough, due to strong Jahn–Taller distortion, the e g energy level of Mn splits, which weakens the interactions between the tetrahedral and the octahedral cations, and enhances interactions between the octahedral cations. Ferromagnetic interactions between octahedral Mn 3+ and AFM interactions between octahedral Mn 2+ become obvious. The magnetic ordering temperature has been raised from 20 K to 93 K as the Mn concentration increases, and the maximum exchange bias field is observed to be 1.063 kOe.