Ferroelectric and piezoelectric properties of PSLZT multilayer / NZFO co-sintered magnetoelectric composites fabricated by tape casting

Abstract

In this study we investigated the ferroelectric and piezoelectric behaviour of co-sintered magnetoelectric composite fabricated by tape-casting method using Pb(1-x-3y/2)SrxLay(Zrz,Ti(1-z))O3 piezoelectric ceramic with x = 0.06, y = 0.03, z = 0.56 (PSLZT) multilayer and Ni0.6Zn0.4Fe2O4 (NZFO). PSLZT and NZFO powders were prepared by solid state reaction method and respective thick films were fabricated by tape casting method. PSLZT multilayer with Pt inner electrodes were laminated with NZFO and co-sintered at 1060 °C for 2 h to obtain delamination free layered composite. Scanning electron microscopy was employed to analyse the microstructure and interface of the co-sintered multilayer which are crucial for elastic coupling. Micrographs recorded across the cross section of the composites revealed insignificant interdiffusion between the phases. Individual piezoelectric multilayer and magnetoelectric composites were analysed for their ferroelectric behaviour. Piezo Force Microscopy (PFM) and Magnetic Force Microscopy (MFM) were utilized to study the ferroelectric domains and magnetic domains on top surface of PSLZT multilayer and NZFO, respectively in composite structure. Ferroelectric behaviour of PSLZT multilayer - NZFO composite was recorded and compared with 3 layered PSLZT. The values of remanent polarization were found to be 50.6 μC/cm2 and 55 μm/cm2 whereas capacitance at 1 Hz found to be 31.5 nF and 28.9 nF for PSLZT multilayer and PSLZT multilayer – NZFO composite respectively. Piezoelectric coefficient of PSLZT multilayer was found to be 980–1030 pC/N whereas for PSLZT multilayer – NZFO composites it was 1050–1150 pC/N. Magnetoelectric coefficient of 150 mV/cm.Oe was obtained for the same composite structure.