Publication Type
Journal
Journal Name
Physical Review B
Publication Date
Volume
104
Issue
6
Abstract
Due to the strong coupling between magnetism and ferroelectricity, (ND4)2FeCl5⋅D2O exhibits several intriguing magnetic and electric phases. In this Letter, we include higher-order onsite anisotropic spin interactions to explain the ferroelectric phase transitions of (ND4)2FeCl5⋅D2O in a magnetic field and to produce the large weights of high-order harmonic components in the cycloid structure that are observed from neutron diffraction experiments. Moreover, we predict a new ferroelectric phase sandwiched between the FE II and FE III phases in a magnetic field. By emphasizing the importance of the higher-order spin anisotropic interactions, our work provides a framework to understand multiferroic materials with rich phase diagrams.
