Phenomenological theory of magnetoelectric coupling in granular multiferroics

Article

关键词: FERROELECTRIC PROPERTIES;    MANIPULATION;   

DOI  :  10.1103/PhysRevB.92.045406

来源: SCIE

【 摘 要 】

We study the coupling between the ferroelectric polarization and themagnetization of a granular ferromagnetic film using a phenomenological model of a combined multiferroic system consisting of a granular ferromagnetic film placed above a ferroelectric (FE) layer. The coupling is due to the screening of the Coulomb interaction in the granular film by the FE layer. Below the FE Curie temperature, the magnetization has a hysteresis as a function of the electric field. Below the magnetic ordering temperature, the polarization has a hysteresis as a function of the magnetic field. We study the magnetoelectric coupling for weak and strong spatial dispersion of the FE layer. The effect of mutual influence decreases with increasing spatial dispersion of the FE layer. For weak dispersion, the strongest coupling occurs in the vicinity of the ferroelectric-paraelectric phase transition. For strong dispersion, the situation is the opposite. We study the magnetoelectric coupling as a function of the distance between the FE layer and the granular film. For large distances, the coupling decays exponentially due to the exponential decrease of the electric field produced by the oscillating charges in the granular ferromagnetic film.

【 授权许可】

Free