Effect of Growth Conditions on Structural and Electrical Properties of Pb(Zr_xTi_(1-x))O_3 layers grown by peroxide MBE

摘要

Pb(Zr_xTi_(1-x))O_3 (PZT) films were grown by molecular beam epitaxy using hydrogen peroxide as a source of reactive oxygen. Phase composition as well as structural and electrical properties of the films were studied by x-ray diffractometry, scanning and transmission electron microscopy, conductive atomic force microscopy, and electrical (I-V and polarization-field) measurements. The hydrogen peroxide pressure was found to control the phase composition of the films. Excess peroxide leads to PbO inclusions in PZT layers, whereas deficiency results in the TiO_2 or the ZrO_2 phase. The second-phase inclusions can be responsible for high leakage current in the films. Precise control over the peroxide pressure is imperative for single-phase PZT films with good ferroelectric properties.