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 antiferrromagnetic 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 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 as well as a quadratic dependence on the external magnetic field.
利用热力学、磁学和介电测量研究了四元尖晶石Mn $_3$ O $_4$中与自旋有序转变相关的介电异常。我们发现，Mn $_3$ O $_4$中的三个磁有序转变中的两个导致了零外加磁场下随温度变化的介电常数的降低.施加磁场的多晶样品离开这两个介电异常几乎不变，但导致介电常数的增加，在中间自旋有序过渡。我们讨论了这种磁介电行为的自旋-声子耦合的可能起源。能带结构的计算表明，在其亚铁磁态，Mn $_3$ O $_4$对应于一个半导体没有轨道简并由于强Jahn-Teller失真。
Observation of 300 K High Energy MagnetoDielectric Response in the Bilayer Manganite (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_2$O$_7$
我们在双层锰氧化物（La $_{0.4}$ Pr $_{0.6}$）$_{1.2}$ Sr $_{1.8}$ Mn $_2$ O $_7$中观察到大的HEMD效应，这是场驱动的自旋玻璃绝缘体到铁磁金属转变的直接结果。过渡的残余物可用于在室温下实现介电对比度。这一发现表明，电子机制，如金属-绝缘体转变，电荷排序，和轨道排序，可以利用在其他材料中提供实质性的介电对比度。
Magnetocapacitance as a sensitive probe of magnetostructural changes in NiCr$_2$O$_4$
尖晶石NiCr $_2$ O $_4$的特征在于使用介电和高磁场测量。磁介电响应的趋势落入三个明确的温度制度对应于已知的磁性和结构转变。在65 ° K以上，观察到介电常数对弱磁场的依赖性，没有滞后。当30\，K\，$\leq\,T\,\leq$\，65\，K时，观察到介电常数对磁场的强烈依赖性，并且滞后发展，导致所谓的蝴蝶环。在30 ℃以下，磁介电滞后增强.磁介电磁滞反映了磁滞，表明自旋-自旋相互作用是NiCr $_2$ O $_4$中磁电效应的机制。然而，在高磁场下，磁化强度继续增加，而介电常数饱和。NiCr $_2$ O $_4$的磁介电测量结果表明，在20 K时存在一个额外的先前未观察到的转变。磁性和结构的细微变化表明，这种20，K异常对应于亚铁磁有序化的完成和自旋驱动的结构畸变。我们证明了磁电容是磁结构畸变的灵敏探针。
Field-tunable partial antiferromagnetism, glassy spin dynamics, and magnetodielectric coupling in the quasi-one-dimensional spin-chain compound Ca3CoIrO6
The 6H-perovskites Ba$_3$RRu$_2$O$_9$ (R = rare earth element) demonstrate the magnetodielectric (MD) coupling as a manifestation of $4d - 4f$ magnetic interactions. Here, we have reported a detailed study of the structural, magnetic, heat capacity, and MD properties of the 6H-perovskite Ba$_3$GdRu$_2$O$_9$. The signature of long-range antiferromagnetic (AFM) ordering $\sim$ 14.8 K ($T_N$) is evident from the magnetization and heat capacity studies. The $T_N$ shifts towards the lower temperature side, apart from splitting in two with the application of the magnetic field. Field-dependent magne…
