Multiferroicity and magnetoelectric coupling in alpha-CaCr2O4

Article

关键词: POLARIZATION;    REVERSAL;   

DOI  :  10.1103/PhysRevB.84.064129

来源: SCIE

【 摘 要 】

Ferroelectricity in the incommensurate helical magnetic phase (below T-N, 43 K) of alpha (alpha) CaCr2O4 has been confirmed by pyroelectric measurements. Magnetoelectric and magnetodielectric coupling exist below T-N 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 exhibits a vanishingly small value below the first-order transition at T-N, as observed experimentally.

【 授权许可】

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