Interfacial Effects on Multiferroic Properties of Pb(Zr_0.52Ti_0.48)O₃/Ni_0.8Zn_0.2Fe₂O₄ Bilayer Thin Films by Pulsed Laser Deposition

Abstract

Bilayer multiferroic thin films of Pb(Zr_0.52Ti_0.48)O₃/Ni_0.8Zn_0.2Fe₂O₄ (PZT/NZF) were prepared on SrTiO₃(001) substrate via pulsed laser deposition. X-ray diffraction results showed the highly epitaxial (001)-orientation of the bilayer thin films were successfully fabricated. The remnant polarization 2P_r and coercive field E_c are 98.3μC/cm² and 370kV/cm in the bilayer thin films, 46.1μC/cm² and 115kV/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/cm³ and 273.6Oe 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.

Keywords:

• magnetoelectric
• PLD
• PZT
• NZF
• strain