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arXiv 1104.4932cond-mat.mtrl-sci
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α- CaCr2O4的多铁性和磁电耦合

Multiferroicity and magnetoelectric coupling in α-CaCr2O4

Kiran Singh, Charles Simon, Pierre Toledano

摘要:

通过热释电测量证实了α-CaCr_2 O_4的无公度螺旋磁相(低于TN,43 K)的铁电性。在TN以下存在磁电和磁介电耦合,且与磁场的平方成正比。从对称性分析,我们认为,外部电场的存在不稳定的对称2221'相和稳定的21'对称性。这提供了一个独特的系统,其中偏振变化的顺序参数振幅的第四度,并表现出一个消失的小值低于一阶过渡在TN,如实验所观察到的。

英文摘要:

Ferroelectricity in the incommensurate helical magnetic phase (below TN, 43K) of alpha CaCr2O4 has been confirmed by pyroelectric measurements. Magnetoelectric and magnetodielectric coupling exist below TN and are proportional to the square of magnetic field. From symmetry analysis, we suggest that the presence of an external electric field destabilizes the symmetrical 2221' phase and stabilizes 21' symmetry. This provides a unique system in which polarization varies as the fourth-degree of the order-parameter amplitude and exhibit a vanishingly small value below the first-order transition at TN, as observed experimentally.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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