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arXiv · 0909.1159

Magnetoelectric Properties of (Ca$_{1-x}$Sr$_{x}$)$_2$CoSi$_2$O$_7$ Crystals

M. Akaki·J. Tozawa·M. Hitomi·D. Akahoshi·H. Kuwahara
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Abstract

We have investigated the magnetoelectric properties of (Ca$_{1-x}$Sr$_{x}$)$_2$CoSi$_2$O$_7$ ($0\leq x\leq 1$) crystals with a quasi-two-dimensional structure. In Ca$_2$CoSi$_2$O$_7$ ($x=0$), a canted antiferromagnetic transition occurs at 5.6 K. The transition temperature $T_{\rm N}$ is increasing with increasing Sr concentration, and the rises of the magnetization and dielectric constant become larger. Since the dielectric constant shows large change at $T_{\rm N}$ and the magnetocapacitance effect is observed below $T_{\rm N}$, a coupling between the magnetism and dielectricity is strong in (Ca$_{1-x}$Sr$_{x}$)$_2$CoSi$_2$O$_7$. The positive magnetocapacitance is reduced by Sr substitution, and is not observed in $x\geq 0.5$. Namely, the compound of $x\geq 0.5$ does not show the magnetic-field-induced electric polarization. On the other hand, the negative magnetocapacitance is enhanced by Sr substitution.

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M. Akaki, J. Tozawa, M. Hitomi, D. Akahoshi, H. Kuwahara. 2009-09-07. Magnetoelectric Properties of (Ca$_{1-x}$Sr$_{x}$)$_2$CoSi$_2$O$_7$ Crystals. https://doi.org/10.1088/1742-6596/200/1/012003

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