Multiferroic epitaxial Pb(Fe1∕2Nb1∕2)O3 thin films: A relaxor ferroelectric/weak ferromagnet with a variable structure

Abstract

The authors report the structural, ferroelectric, and ferromagnetic properties of Pb(Fe1∕2Nb1∕2)O3 epitaxial thin layers grown on (001), (110), and (111) SrTiO3 substrates by pulsed-laser deposition; films were of sufficient resistivity to enable high-field P-E measurements. Findings are as follows: epitaxial strain results in (i) a dramatic increase in the spontaneous polarization Ps; (ii) a lattice structure that is dependent on substrate orientation; (iii) a slim-loop P-E response and relaxor ferroelectric characteristics in the dielectric constant, both of which are nearly independent of crystallographic orientation; and (iv) a weak ferromagnetic moment, which is dependent on epitaxial mismatch.