High temperature x-ray diffraction studies of zirconia thin films prepared by reactive pulsed laser deposition

摘要

Zirconium oxide thin films have been deposited on Si (100) substrates at room temperature at an optimized oxygen partial pressure of 3x10~(-2) mbar by reactive pulsed laser deposition. High temperature x-ray diffraction (HTXRD) studies of the film in the temperature range room temperature-1473 K revealed that the film contained only monoclinic phase at temperatures ≤ 673 K and both monoclinic and tetragonal phases were present at temperatures ≥ 773 K. The tetragonal phase content was significantly dominating over monoclinic phase with the increase of temperature. The phase evolution was accompanied with the increase in the crystallite size from 20 to 40 nm for the tetragonal phase. The mean thermal expansion coefficients for the tetragonal phase have been found to be 10.58x10~(-6) K~(-1) and 20.92x10~(-6) K~(-1) along a and c-axes, respectively. The mean volume thermal expansion coefficient is 42.34x10~(-6) K~(-1) in the temperature range 773-1473 K.