X-ray diffraction analysis of texture modification induced by ion beam irradiation in stainless steel films

Microstructural, mechanical and textural state evolution under Kr irradiation have been analysed in 250 and 500 nm sputter deposited 304L stainless steel films using X-ray diffraction measurements. The as-sputtered films are in a high compressive stress state (between 3.2 and 2.4 GPa) and show a fibre texture which nature depends on the film thickness: <110> and <111> for 500 nm thick films and only <110> for 250 nm thick. A 150 nm in depth high fluence Kr2+ irradiation induces a decrease of the in plane stress values and textural modifications in both films; the <110> fibre texture in the 250 nm thick film disappears completely whereas in the 500 nm thick film, the <111> fibre texture is destroyed while the <110> fibre texture is still present. These results confirm the existence of a critical thickness (300 nm) above which a columnar structure with <111> fibre texture takes place during thin film growth. (C) 2004 Elsevier B.V. All rights reserved.