Structural and Electrical Characterization of Lead Metaniobate Thin Films Deposited by Pulsed Laser Ablation

摘要

Lead niobate thin films have been prepared by laser ablation, at different substrate temperatures (T_(dep)) and with different oxygen pressures (pO_2). For low deposition temperatures the films presented a rhombohedric-PbNb2O_6 structural phase, with hysteresis cycles characteristic of a paraelectric. As T_(dep) increased the films started to develop an orthorhombic-PbNb_2O_6 structure that appeared at 400 deg C and remained up to 600 deg C. For low pO_2, a mixture of this phase and a lead deficient phase was present in the films. Increasing the oxygen pressure the lead deficient phase was strongly reduced and the films presented only the ferroelectric orthorhombic-PbNb_2O_6 structural phase.