CoSeO4 中的磁有序和磁电现象。

Magnetic ordering and magnetodielectric phenomena in CoSeO4.

机构信息

Materials Department and Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.

出版信息

J Phys Condens Matter. 2010 Dec 22;22(50):506003. doi: 10.1088/0953-8984/22/50/506003. Epub 2010 Nov 30.

Abstract

CoSeO(4) has a structure consisting of edge-sharing chains of Co(2+) octahedra which are held together by SeO(4)(2-) tetrahedra via shared oxygen atoms at the edges of the octahedra. DC magnetization measurements indicate a transition to an ordered state below 30 K. Powder neutron diffraction refinements suggest an ordered state with two unique antiferromagnetic chains within the unit cell. Isothermal magnetization measurements indicate a temperature-dependent field-induced magnetic transition below the ordering temperature. From neutron diffraction, we find that this corresponds to a realignment of spins from the canted configuration towards the c-axis. The dielectric constant shows a change in slope at the magnetic ordering temperature indicating an interplay between the spin and charge degrees of freedom.

摘要

CoSeO(4) 的结构由钴(2+)的八面体通过共享八面体边缘的氧原子连接而成，这些八面体通过硒氧(4)(2-)四面体连接在一起。直流磁化测量表明，在 30 K 以下会发生向有序状态的转变。粉末中子衍射精修表明，在单位晶胞内存在两个独特的反铁磁链的有序状态。等温磁化测量表明，在有序温度以下存在温度相关的磁场诱导磁转变。从中子衍射中，我们发现这对应于自旋从倾斜配置向 c 轴的重新排列。介电常数在磁有序温度处斜率发生变化，表明自旋和电荷自由度之间存在相互作用。