Artificially induced normal ferroelectric behaviour in aerosol deposited relaxor 65PMN-35PT thick films by interface engineering

Abstract

A thin dielectric layer of Al2O3 was grown by atomic layer deposition on a relaxor ferroelectric 65Pb(Mg1/3Nb2/3)O-3-35PbTiO(3) (PMN-PT)/Pt/Si thick film fabricated by the aerosol deposition technique to artificially induce ferroelectric behaviour. The frequency and temperature-dependent dielectric properties with a reduced degree of diffuseness (gamma, from 1.9 to 1.5) and the change in the shape of the polarization-electric field curves (from slim relaxor with low hysteresis to square type ferroelectric with high hysteresis) confirm the modulation of its pristine relaxor ferroelectric nature with a change in the Al2O3 layer thickness. An increase in the maximum dielectric temperature (T-m), remnant polarisation (P-r), coercive field (E-c), and impedance was observed with increasing thickness of the Al2O3 dielectric layer, which can be attributed to the accumulation of charge carriers at the interface of the Pt/Al2O3/PMN-PT/Pt/Si heterostructure in the presence of an external electric field. Leakage characteristics also support the artificially induced ferroelectric behaviour in the Pt/Al2O3/PMN-PT/Pt/Si heterostructure. The aftereffects of the dielectric Al2O3 interface layer over the relaxor ferroelectric film is discussed in detail.