Vijayanandhini K, Simon Ch, Pralong V, Bréard Y, Caignaert V, Raveau B, Mandal P, Sundaresan A, Rao C N R
CRISMAT, UMR 6508, CNRS-ENSICAEN, Université de Caen, 14050 Caen, France.
J Phys Condens Matter. 2009 Dec 2;21(48):486002. doi: 10.1088/0953-8984/21/48/486002. Epub 2009 Oct 30.
The orthorhombic perovskite, (La(1-x/2)Bi(x/2))(Fe(0.5)Cr(0.5))O(3) was investigated for 0≤x≤1. Its space group, Pnma, compatible with the disordering of iron and chromium in the B sites, confirms previous observations. More importantly this compound is found to be an uncompensated weak ferromagnet, with a very peculiar zero magnetization behaviour, generally observed for ordered magnetic cations in the B sites. It exhibits a magnetic transition at high temperature (T(C)) above 450 K, while the zero magnetization occurs between 100 and 160 K depending on the x-value. The AC magnetic susceptibility study shows that this compound does not exhibit a spin glass or cluster glass behaviour, in contrast to what was suggested for the x = 0 compound. This zero magnetization phenomenon can be interpreted by the fact that this perovskite is an uncompensated weak ferromagnet, which consists of canted weak ferromagnetic domains and clusters of pure chromium and pure iron composition, antiferromagnetically coupled through Cr-O-Fe interactions.
对正交钙钛矿（La(1 - x/2)Bi(x/2))(Fe(0.5)Cr(0.5))O(3)）在0≤x≤1范围内进行了研究。其空间群Pnma与B位中铁和铬的无序状态相匹配，证实了先前的观察结果。更重要的是，该化合物被发现是一种未补偿的弱铁磁体，具有非常奇特的零磁化行为，这种行为通常在B位有序磁性阳离子中观察到。它在高于450 K的高温（T(C)）下表现出磁转变，而零磁化根据x值在100至160 K之间出现。交流磁化率研究表明，与x = 0化合物的情况相反，该化合物不表现出自旋玻璃或团簇玻璃行为。这种零磁化现象可以通过以下事实来解释：这种钙钛矿是一种未补偿的弱铁磁体，它由倾斜的弱铁磁畴以及纯铬和纯铁组成的团簇构成，通过Cr - O - Fe相互作用进行反铁磁耦合。
