Interfacial Effects on Multiferroic Properties of Pb(Zr_(0.52)Ti_(0.48))O_3/Ni_(0.8)Zn_(0.2)Fe_2O_4 Bilayer Thin Films by Pulsed Laser Deposition

摘要

Bilayer multiferroic thin films of Pb(Zr_(0.52)Ti_(0.48))O_3/Ni_(0.8)Zn_(0.2)Fe_2O_4 (PZT/NZF) were prepared on SrTiO_3(001) substrate via pulsed laser deposition. X-ray diffraction results showed the highly epitaxial (OOl)-orientation of the bilayer thin films were successfully fabricated. The remnant polarization 2P_r and coercive field E_c are 98.3p,C/cm~2 and 370kV/cm in the bilayer thin films, 46.1/xC/cm~2 and 115/cV/cm in the pure PZT film. The polarization and electric breakdown voltage were enhanced by about one time, which may be attributed to the tensile stress of the NZF layer onto the PZT layer, resulting in the elongated c-axis of the PZT. In addition, the saturation magnetization and coercive field for the bilayer films are 256.2emu/cm~3 and 273.60e in-plane, respectively. As a comparison, the corresponded values for the pure NZF film are 270.8emu/cm3 and 367.3Oe in-plane, which revealed that the ferromagnetic properties of the bilayer films have been decreased, which may be due to the compressive stress of the PZT layer under the NZF layer. Our results indicate that the existing interfacial strain in PZT/NFO bilayer films can result in the improvement of the ferroelectric properties and the reduction of the ferromagnetic properties.