Previous reports depict that the nonstoichiometric Co/Mn ratio greatly affects the physical properties of Ca₃CoMnO₆, but few papers focus on the Co/Mn site doping effect. In order to investigate the influence of the substitution on the magnetization, partial Mn⁴⁺ ions were replaced with Al³⁺ ions and polycrystalline Ca₃CoMn_1-xAl_xO₆ (x = 0, 0.05, 0.1, 0.15, 0.2) samples were prepared. All the samples crystallized into rhombohedral structure without existence of impurities. SEM patterns showed that the mean particle size decreased with the introduction of Al element. Due to the dilution effect of nonmagnetic Al³⁺ ions to the spin chains, the competing short-range antiferromagnetic/ferromagnetic order caused by the “order by disorder” phenomenon was suppressed. The high-temperature spin freezing peak disappeared gradually and the doped samples presented a faster dynamic behavior, indicating a more robust long-range antiferromagnetic order. The time-dependent magnetization showed a nonmonotonic relaxation in a field of 5T, implying the possible existence of quantum tunneling of magnetization.

先前的报道表明，非化学计量的Co / Mn比会极大地影响Ca ₃ CoMnO ₆的物理性能，但很少有论文关注Co / Mn的位点掺杂效应。为了研究在磁化的取代的影响，局部的Mn ⁴⁺离子被用Al置换³⁺离子和多晶的Ca ₃期CoMn _{1- X}的Al _X ø ₆（X = 0、0.05、0.1、0.15、0.2）的样品已准备好。所有样品结晶成菱形结构，不存在杂质。扫描电镜（SEM）图谱表明，随着Al元素的引入，平均粒径减小。由于非磁性Al ³⁺离子对自旋链的稀释作用，抑制了由“无序排列”现象引起的竞争性短程反铁磁/铁磁有序。高温自旋冻结峰逐渐消失，掺杂样品呈现出更快的动力学行为，表明更强的远距离反铁磁序。随时间变化的磁化强度在5T场中显示出非单调弛豫，这意味着可能存在磁化强度的量子隧穿。