Exploring the processing conditions to optimize the interface in 2-2 composites based on Pb(Zr,Ti)O3 and NiFe2O4

The processing of laminated composites based on lead zirconate titanate and nickel ferrite was investigated. Ceramic powders were prepared by solid-state reaction and sintered by conventional and hot pressing method, under different time and temperature conditions. As expected, it is found that differences in the grain size and thermal expansion coefficients between the constituent phases can cause a shear breaking of the material and excessive crack formation. Such problems were considerably reduced with the manufacture of several layers of particulate composites to create a stepwise crossover at the interface between both laminated phases. The results in this work show the way to obtain hot-pressed magnetoelectric composites with optimized interface, and they demonstrate that micro-cracks may lower the magnetoelectric effect by several orders of magnitude.