The surface and in-depth compositions of sputter-deposited Cu0.57Ni0.42Mn0.
01 thin films were studied by Auger electron depth profiling after thermal
treatment. The samples were thermally cycled to maximum temperatures of 300
degrees C in air, argon and forming gas (N-2, 5 vol. % H-2). Linear least-
squares fit to standard spectra and factor analysis were applied to separat
e the overlapping Auger transitions of Cu and Ni.
Under bombardment by 4 keV argon ions, CuNi(Mn) layers display bombardment-
induced surface enrichment of Ni in the same extent as binary CuNi alloys.
At sufficiently high oxygen partial pressures, a duplex oxide layer is form
ed and a thick surface copper oxide overgrows the initial nickel oxide. In
reducing atmosphere selective oxidation of manganese takes place.
A capping NiCr layer prevents CuNi(Mn) from being oxidized, but the film co
nfiguration is degraded with increasing annealing temperature due to format
ion of a surface chromium oxide and diffusion of Ni from the CuNi(Mn) layer
into the NiCr/CuNi(Mn) interface.