Crystallographic and magnetic properties of the mixed-valence oxides CaRu 1-x Mn x O 3
Crystallographic and magnetic properties of the mixed-valence oxides CaRu 1-x Mn x O 3
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DOI：
10.1103/physrevb.77.014406
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发表时间：
2008-01
影响因子：
3.7
通讯作者：
T. Taniguchi;S. Mizusaki;N. Okada;Y. Nagata;S. Lai;M. Lan;N. Hiraoka;M. Itou;Y. Sakurai;T. C. Ozawa;Y. Noro;H. Samata
中科院分区：
文献类型：
--
作者：
T. Taniguchi;S. Mizusaki;N. Okada;Y. Nagata;S. Lai;M. Lan;N. Hiraoka;M. Itou;Y. Sakurai;T. C. Ozawa;Y. Noro;H. Samata
通过X射线粉末衍射、磁化强度和磁康普顿散射测量，详细研究了的晶体学和磁性。晶格参数显示出相当大的偏离Vegard定律。铁磁性出现在一个相对较大的Mn浓度，和磁化强度和居里温度有一个最大值在Mn含量附近。磁康普顿散射测量表明，Mn使磁化强度的主要贡献和Mn的力矩是反平行的Ru的力矩，这是由Mn掺杂诱导。根据、和离子的混合价模型讨论了晶胞体积的异常变化和铁磁性的发生。假设（1）和Mn离子之间的铁磁耦合，（2）和Mn离子之间的反铁磁耦合，（3）、、和的理论自旋矩，半定量地解释了自发磁化强度与Mn组分的关系。离子间的铁磁相互作用似乎对居里温度起主要作用。这种铁磁是由Mn离子间的铁磁相互作用与Mn离子间的反铁磁相互作用竞争而产生的亚铁磁体。
The crystallographic and magnetic properties ofwere investigated in detail by x-ray powder diffraction, magnetization, and magnetic Compton scattering measurements. The lattice parameters show considerable deviation from Vegard’s law. Ferromagnetism appears at a relatively large Mn concentration, and the magnetization and the Curie temperature have a maximum at a Mn content near. The magnetic Compton scattering measurement revealed that Mn makes a dominant contribution to the magnetization and the Mn moment is antiparallel to the Ru moment, which is induced by Mn doping. The anomalous change in the unit cell volume and the occurrence of ferromagnetism were discussed on the basis of the mixed-valence model of,,, andions. The Mn-composition dependence of the spontaneous magnetization was explained semiquantitatively assuming (1) ferromagnetic coupling betweenandions, (2) antiferromagnetic coupling betweenand Mn ions, and (3) the theoretical spin moments of,, and. The ferromagnetic interaction betweenandions seems to make a dominant contribution to the Curie temperature. Thesystem is considered to be a ferrimagnet induced through competition between the ferromagnetic interaction between Mn ions and the antiferromagnetic interaction betweenand Mn ions.