Effect of substrate temperature on magnetic and microstructural properties of sputtered Co-Cr films with perpendicular magnetic anisotropy

Co-22 at.%Cr films with perpendicular magnetic anisotropy have been sputter-deposited onto glass substrates at various substrate temperatures from room temperature to 230°C. A systematic X-ray analysis has shown that higher substrate temperatures such as 200°C promote the pronounced asymmetric nature in the X-ray profile of Co-Cr films. Co-Cr films deposited at high substrate temperatures are composed of at least two regions differing in crystallinity, implying a microscopic stratified nature along the film thickness. Correlation of such a microstructure with a segregation mechanism and resultant magnetic properties is described. In addition to the magnetocrystalline anisotropy of Co-Cr films, it is suggested that surface or interface anisotropy due to the stratified structure might be present