Ferroelectricity in the 1 μC cm~(-2) range induced by canted antiferromagnetism in (LaMn_3)Mn_4O_(12)

摘要

Pyroelectric current and field-dependent specific heat measurements on polycrystalline samples of the quadruple perovskite (LaMn3)Mn4O12 give evidence of ferroelectricity driven by the canted antiferromagnetic ordering of the B-site Mn3+ ions at TN,B=78 K with record large remnant electric polarization up to 0.56 mu C cm(-2). X-ray diffraction measurements indicate an anomalous behavior of the monoclinic beta angle at TN,B, which suggests that the polarization lies in the ac-plane, where the moments are collinear, and that symmetric exchange striction is the mechanism of spin-driven ferroelectricity. Polarization values up to similar to 3-6 mu C cm(-2) are expected in single crystals or epitaxial films, which would enable the development of practical multiferroic applications.