We study the magnetocapacitance (MC) effect and magnetoelectric (ME) coupling in spin-flop driven antiferromagnet Co4Ta2O9. The magnetocapacitance data at high magnetic fields are analyzed by phenomenological Ginzburg-landau theory of ferroelectromagnets and it is found that change in dielectric constant is proportional to the square of magnetization. The saturation polarization and magnetoelectric coupling are estimated to be 52microC/m2 and $\gamma$ = 1.4 x10-3 (emu/g)-2 respectively at 6 Tesla. Electric polarization is achieved below Neel temperature only when the sample is cooled in the presence of magnetic field and it is established that the ground state is non-ferroelectric implying that magnetic lattice does not lead to spontaneous symmetry breaking in Co4Ta2O9.

中文翻译：

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刚玉反铁磁体Co4Ta2O9中磁电耦合的性质

我们研究了自旋触发器驱动的反铁磁体 Co4Ta2O9 中的磁电容 (MC) 效应和磁电 (ME) 耦合。通过铁电磁体的现象学Ginzburg-landau理论分析了强磁场下的磁电容数据，发现介电常数的变化与磁化强度的平方成正比。在 6 特斯拉下，饱和极化和磁电耦合估计分别为 52microC/m2 和 $\gamma$ = 1.4 x10-3 (emu/g)-2。只有当样品在磁场存在下冷却时才能实现电极化，并且确定基态是非铁电的，这意味着磁性晶格不会导致 Co4Ta2O9 中的自发对称性破坏。