マルチフェロイック複合材料の微視構造と材料組合せに関するマルチスケール数値解析研究

抄録

In this study a multiscale numerical simulation was presented for multiferroic composite materials consisting of ferroelectric (FE) and ferromagnetic (FM) phases to design the microstructure and the material combination. An asymptotic homogenization theory was employed to estimate macroscopic homogenized material properties. We focused on three-type conventional microstructures, a polycrystalline random structure, a polycrystalline layered structure, and a single-crystalline layered structure. On the other hand, three typical materials, barium titanate, lead titanate and PZT, were utilized for FE phase. In addition, two materials, cobalt ferrite and Terfenol-D, were selected for FM phase. At first the influence of the volume fraction of FE phase on macroscopic homogenized material properties was investigated for every condition. The optimum volume fraction was found to maximize macroscopic magnetoelectric (ME) effect. The ME coefficient at the optimum volume fraction was compared among three-type microstructures and six-type material combinations. We discussed how to determine the microstructure, the material combination and the volume fraction to get the maximum ME effect.