Nature of the pulsed laser process for the deposition of high Tc superconducting thin films

Factors which affect the deposition of high-Tc superconducting thin films by pulsed-laser deposition technique were investigated using laser ionization mass spectrometry to identify the ionic species emitted from a superconducting YBa2Cu3O(7-x) target under laser irradiation and the post- ablation ionization neutral velocity analysis technique to determine the mass and velocities of the ejected material. X-ray absorption measurements were performed on films deposited onto substrates in order to identify the presence of short-range crystalline order in the films. The results of the X-ray and the laser microprobe analyses indicate the absence of stoichiometric clusters in the plume of the material ejected in the laser interaction with the pellet. There was evidence for the presence of energetic nonthermal species in the ejected plume of material, which could significantly influence the growth of high-quality crystalline films at lower substrate temperatures. (I.S.)