Preparation of thin film of CaZrO 3 by pulsed laser deposition

Abstract

Thin films of CaZrO 3 are prepared by pulsed laser deposition (PLD) using a 532-nm Q-switched Nd:YAG laser. Films prepared in vacuum, on annealing, revealed the structure of calcia stabilized zirconia, i.e. Ca 0.15Zr 0.85O 1.85. Films prepared in the presence of 150×10 −3 Torr of oxygen, on annealing, have CaZrO 3 structure, though a small percentage of Ca 0.15Zr 0.85O 1.85 is still present. Larger oxygen pressures during film deposition lead to the presence of many other oxides of a greater oxygen mole fraction in the film. Particulate deposition that leads to undesirable properties for the films is observed in the scanning electron microscopy (SEM) when the film is prepared using a laser fluence of the order of 16 J/cm 2, whereas the fluence 0.64 J/cm 2 produced particulate-free films. The vapor composition and the velocities of the different species (in vacuum) are determined using a quadrupole mass spectrometer (QMS), and the laser ablation process under the film deposition condition (laser fluence 0.64 J/cm 2) is found to be thermal. The deficiency in Ca observed for the film prepared in vacuum appears to correlate with a deficiency in CaO +. The observed difference in the stoichiometry of the films deposited under vacuum and oxygen background is discussed based on the mass spectrometry results.