Composition and crystalline properties of TiNi thin films prepared by pulsed laser deposition under vacuum and in ambient Ar gas

Abstract

TiNi shape memory alloy thin films were deposited using the pulsed laser deposition under vacuum and in an ambient Ar gas. Our main purpose is to investigate the influences of ambient Ar gas on the composition and the crystallization temperature of TiNi thin films. The deposited films were characterized by energy-dispersive X-ray spectrometry, a surface profiler, and X-ray diffraction at room temperature. In the case of TiNi thin films deposited in an ambient Ar gas, the compositions of the films were found to be very close to the composition of target when the substrate was placed at the shock front. The in-situ crystallization temperature (ca. 400A degrees C) of the TiNi film prepared at the shock front in an ambient Ar gas was found to be lowered by ca. 100A degrees C in comparison with that of a TiNi film prepared under vacuum.