New lead free magnetoelectric composites with high performance

Abstract

Magnetoelectric materials promise, in the near future, to revolutionize the concept of electric and magnetic devices. Possible fields of application span-from several types of sensors and energy harvesters, to biomedical applications as cure of Parkinson's Disease and cancer. Even though materials with high magnetoelectric coupling were developed in last years, best results have been found in lead based and/or using patented metallic alloys composites. In this way, the aim of this project is to obtain environmentally friendly magnetoelectric composites with improved properties, constituted by a piezoelectric Ba0.85Ca0.15Ti0.9Zr0.1O3 and magnetostrictive CoMn0.25Fe1.75O4 phases. Due to the good piezoelectric and magnetic properties of the constituent phases, a high magnetoelectric response would be expected after otimization, which could put these materials as an environmentally friendly alternative for future applications. Firstly, properties of the single phases will be correlated with the method and conditions of synthesis and sintering. After that, magnetoelectric laminated composites will be prepared as three-layers and multilayers. Spark plasma sintering will be investigated as a suitable technique to obtain high quality materials with tailored interfaces. Multilayers composites, for which the highest magnetoelectric coefficients are expected, will be shaped using tapes prepared by Tape Casting; therefore, a detailed study of the rheological properties and stability of suspensions will be essential to obtain good quality composites. Finally, composites will be characterized to identify possible factors affecting magnetoelectric coupling and adjust them to maximize the target properties. (AU)