Investigation on (Sr,Co)Bi2Nb2O9 thin films: A lead-free room temperature multiferroics

Novel room temperature single phase multiferroic 10% Co doped SrBi2Nb2O9 (SCBN) thin films were fabricated on Pt/Ti/SiO2/Si(100) substrate by pulse laser deposition. The surface morphology indicates homogeneous grains with average grain size and surface roughness of similar to 40-130 nm and 6 nm, respectively. High dielectric constant, low dielectric loss <2-5%, negligible frequency independent conductivity, moderate polarization, frequency dependent coercive field, and weak saturation magnetization were observed. The change in the shape of magnetic hysteresis and values of coercive field along in-plane and out-of-plane M-H hysteresis indicates a magnetic anisotropy. The presence of magnetic moments and electric dipole in the same plane suggest mutual cooperation between electric and magnetic ordering on the mesoscopic and microscopic scale. (C) 2010 WILEY-VCH Veriag GmbH & Co. KGaA, Weinheim