Magnetically driven ferroelectric order in Ni3V2O8 -: art. no. 087205
Magnetically driven ferroelectric order in Ni3V2O8 -: art. no. 087205
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DOI：
10.1103/physrevlett.95.087205
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发表时间：
2005-08-19
影响因子：
8.6
通讯作者：
Ramirez, AP
中科院分区：
文献类型：
--
作者：
Lawes, G;Harris, AB;Ramirez, AP
我们发现，长程铁电和无公度磁序同时出现在一个单一的相变在Ni3V2O8。自发极化的温度和磁场的依赖性显示出强烈的磁和铁电订单之间的耦合。利用连续相变的朗道理论确定了磁对称性，表明自旋结构本身可以破坏空间反转对称性，从而导致铁电有序。这一唯象理论解释了我们的实验观察，自发极化被限制在沿着晶体B轴，并预测的幅度应该是成比例的磁序参量。
We show that long-range ferroelectric and incommensurate magnetic order appear simultaneously in a single phase transition in Ni3V2O8. The temperature and magnetic-field dependence of the spontaneous polarization show a strong coupling between magnetic and ferroelectric orders. We determine the magnetic symmetry using Landau theory for continuous phase transitions, which shows that the spin structure alone can break spatial inversion symmetry leading to ferroelectric order. This phenomenological theory explains our experimental observation that the spontaneous polarization is restricted to lie along the crystal b axis and predicts that the magnitude should be proportional to a magnetic order parameter.