论文标题
LA2-XCAXCOMNO6系列中的自发交换偏差效应
The spontaneous exchange bias effect in La2-xCaxCoMnO6 series
论文作者
论文摘要
X射线衍射和磁力测定法研究了多晶LA2-XCAXComno6（0 $ \ leq $ x $ \ leq $ 0.75）的结构，电子和磁性。所有样品均具有正交结构，并呈掺杂量的单位细胞略有下降。依赖温度的磁化测量结果揭示了具有两个铁磁过渡的复杂磁性行为。这些过渡归因于CO2+ -MN4+和CO3+ -MN3+耦合，并暗示在这些无序化合物中存在其他抗磁磁耦合。在零外部磁场中冷却样品后测量的场依赖性磁化曲线揭示了CA掺杂样品的自发交换偏置（SEB）效应。由抗铁磁相增加引起的未补偿磁耦合在界面上的加强解释了SEB的增加，而CA含量的增加。
Structural, electronic and magnetic properties of polycrystalline La2-xCaxCoMnO6 (0 $\leq$ x $\leq$ 0.75) compounds are investigated by x-ray diffraction and magnetometry. All the samples have an orthorhombic structure and show a slight decrease in the unit cell with Ca-doping. Temperature-dependent magnetization measurements reveal a complex magnetic behavior with two ferromagnetic transitions. These transitions are ascribed to Co2+--Mn4+ and Co3+--Mn3+ couplings and suggest the presence of additional antiferromagnetic couplings in these disordered compounds. Field-dependent magnetization curves, measured after cooling the samples in a zero external magnetic field, reveal the spontaneous exchange bias (SEB) effect for the Ca-doped samples. The strengthening of the uncompensated magnetic coupling at the interfaces, caused by the increased antiferromagnetic phase, explains the increase of SEB with increasing the Ca-content.
