Magnetic and electrical properties of R2Mo2O7 pyrochlore compounds
Magnetic and electrical properties of R2Mo2O7 pyrochlore compounds
复制标题
R2Mo2O7烧绿石化合物的磁电性质
DOI：
10.1016/0022-4596(89)90067-4
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发表时间：
1989
影响因子：
3.3
通讯作者：
J. Greedan
中科院分区：
文献类型：
--
作者：
N. Ali;M. Hill;Sunil Labroo;J. Greedan
结合交流磁化率，直流磁化强度在各种应用领域，和电阻率数据的theR2Mo2O7系列的立方烧绿石结构氧化物，R= Nd，Sm，Gd，Tb和Y的五个成员的报告。这些测量扩展了已发表的化合物研究，并有助于澄清和解释磁和电输运性质。金属铁磁体，R= Nd，Sm，和Gd，分别在96，80，和57 K。对于R = Nd和Sm，这很可能是由于Mo（IV）磁矩约为1 μB的有序化。在30 K附近，两种化合物由于络合物R → Mo耦合而在直流磁化中表现出滞后，这引起电阻率最小。对于Gd_2Mo_2O_7，没有低温滞后，表明两个亚晶格在相同的温度下铁磁有序。本文首次报道了半导体Tb_2Mo_2O_7在25K时的磁化强度异常，这种异常可归因于长程或短程磁序，交流磁化率数据证实了Y_2Mo_2O_7的类自旋玻璃相变。的立方晶格常数和电磁性能之间的相关性。
A combination of ac susceptibility, dc magnetization in a variety of applied fields, and electrical resistivity data is reported for five members of theR2Mo2O7series of cubic pyrochlore structure oxides,R= Nd, Sm, Gd, Tb, and Y. These measurements extend published studies on the compounds and aid in the clarification and interpretation of the magnetic and electrical transport properties. The metallic ferromagnetics,R= Nd, Sm, and Gd, order at 96, 80, and 57 K, respectively. ForR= Nd and Sm this is due most likely to ordering of Mo(IV) moments of about 1 μB. Near 30 K both compounds show hysteresis in the dc magnetization due to complexRMo coupling which give rise to resistivity minimum. For Gd2Mo2O7there is no low temperature hysteresis, indicating that both sublattices order ferromagnetically at the same temperature. A magnetization anomaly in semiconducting Tb2Mo2O7at 25 K which is attributed to long range or short range magnetic order is reported for the first time and ac susceptibility data confirm a spin-glass like transition in Y2Mo2O7reported previously. A correlation between the cubic lattice constant and the electrical and magnetic properties is noted.