Microstructural characterisation of TiAl thin films grown by DC magnetron co-sputtering technique

The present study deals with the in situ growth of [111] oriented thin film s of TiAl grown by co-sputtering from high purity Ti and Al targets in a DC magnetron sputtering system. The influence of substrate temperature on the chemical and microstructural changes occurring in TiAl thin films has been investigated in the substrate temperature range 573-873 K. Electron probe microanalysis shows that Al concentration increases from 55.78 to 62,15 at. %, while Ti concentration decreases from 44.22 to 37.85 at.% with increase in the substrate temperature. Atomic force microscopy (AFM) of the TiAl fil ms indicates an increase in the crystallite size with substrate temperature . A fine globular morphology of crystallites with a mean surface area of si milar to 1850 nm(2) at 573 K changes to crystallites with a surface area of similar to 2300 nm(2) at 773 K. (C) 2000 Elsevier Science B.V. All rights reserved.