Fabrication and physical properties of bismuth layer-structured ferroelectric thin films with c-axis orientation epitaxially grown by high-temperature sputtering

摘要

Highly c-axis oriented (Bi3.25Nd0.65Eu0.10)Ti3O12 (BNEuT) thin films were deposited on the Pt(100)/MgO(100) substrates by high-temperature sputtering. The substrate temperature was varied from 550 degrees C to 650 degrees C to examine its effect on the structural, dielectric, ferroelectric, and piezoelectric characteristics of the films, and consequently find the optimal substrate temperature for heteroepitaxial growth of BNEuT thin films. All the films deposited at 580 degrees C-650 degrees C exhibited a high degree of c-axis orientation [alpha((001))] of = 97%. All the films grown heteroepitaxially on Pt(100)/MgO(100) substrates was rotated by +/- 45 degrees with respect to the underlying substrates and had a mainly upward polarization, based on data observed by piezoresponse force microscopy. Judging from the structural, dielectric, ferroelectric, and piezoelectric characteristics, it is shown that the optimal substrate temperature for heteroepitaxial growth of BNEuT films with a high alpha((001)) of 97% and a comparatively large remanent polarization of 2.0 mu C cm(-2) is 580 degrees C. (C) 2019 The Japan Society of Applied Physics