In situ high-temperature X-ray diffraction measurements of Pb(Zr0.58Ti0.42)O3 epitaxial thin films grown on Si substrates

Pb(Zr,Ti)O3 (PZT) thin films with rhombohedral composition of Zr/Ti = 58/42 were epitaxially grown on SrRuO3/Pt/ZrO2/Si(001) substrates by radio frequency (RF) magnetron sputtering and their temperature dependence was investigated. In situ high-temperature X-ray diffraction measurements were conducted by the synchrotron radiation X-ray (SPring-8). The as-deposited PZT thin film showed a tetragonal structure due to a clamping effect from substrates. On heating, the diffraction spot was split into two peaks from 600 °C to 750 °C, while the split peaks were maintained on cooling to room temperature. This result indicates that tetragonal and cubic structures coexisted above 600 °C, whereas cubic to rhombohedral phase transition occurred on cooling. After the high-temperature measurement, the PZT thin films showed large voltage dependence of the converse piezoelectric coefficients (∣e31, f∣) due to the drastic change of the crystallographic structure by the high-temperature treatment.