PT-CR THIN-FILM INTERDIFFUSION PROCESSES AND THE ROLE OF A TI INTERLAYER ON FE (99.998-PERCENT) SUBSTRATES

Auger electron spectroscopy with composition depth profiling was used to study the HV thermal interdiffusion processes of consecutive thin f ilms of Pt, Cr and Ti vapour deposited on Fe substrates. The Ti interl ayer serves as a ''getter'' for possible contaminants (C, N, etc.) dif fusing mostly from the bulk of the metallic substrates. The unbound 0 which was trapped during the vapour deposition of the Cr layer also di ffuses into the Ti layer upon annealing. Although the diffusion of the N, C and 0 was limited by the influence of the Ti interlayer the phas es formed at the respective temperatures were similar to those formed in samples without Ti interlayers. At an annealing temperature of 400- degrees-C in high vacuum no phases were observed while for an annealin g temperature of 500-degrees-C the phase Pt3Cr was detected by XRD. An nealing at 600-degrees-C in HV yielded two phases namely PtCr and PtCr 2. The latter is not indicated on the bulk Pt-Cr phase diagram.