The structure of Ta films and Ta/Fe bilayers and multilayers

The results of crystalline structure investigations of Ta films and Ta/Fe bilayers and multilayers on glass substrates are presented. The layers were deposited by sputtering in Penning discharge at substrate temperature near to room one. It was found that formation of bcc- and β-(tetragonal) Ta phases occurs during Ta layers deposition with preferred {110} and {100} orientation of lattice planes parallel to the substrate surface correspondingly. In Ta/Fe multilayers with Ta layer thickness of 20 nm and 40 nm β-Ta prevails. In Ta films with thickness t > 160 nm bcc phase prevails. The average coherent domain size in Ta/Fe multilayers (in direction perpendicular to the substrate surface) is near to Ta layer thickness. In Ta films with t > 160 nm the average domain size exceeds 100 nm. X-ray diffraction studies of bcc- Ta indicate a compressive stress of 6.5x108 N/m2-1.7x109 N/m2 in the plane of the films