Electrodeposited epitaxialFe100−xCoxfilms onn−GaAs(100)

Abstract

The electrodeposition of epitaxial cube-on-cube Fe{sub 100-x}Co{sub x} films onto (100)-oriented n-GaAs from ferrous ammonium sulfate solutions containing various concentrations of cobalt sulfate is described. The cobalt composition in a series of 400-nm-thick films was found to vary in proportion to the concentration of cobalt sulfate in the electrolyte and six compositions in the range from 0 to 74% were deposited. Epitaxial (100)-oriented bcc films were produced throughout this range, as suggested by symmetrical x-ray diffraction and confirmed by x-ray pole figure measurements. Rocking curve measurements yielded data that could be fitted to the sum of a Lorentzian and a Gaussian, corresponding to the (200) Fe{sub 100-x}Co{sub x} planes and to a residual contribution from GaAs (400), respectively. The full width at half maximum obtained for the film Lorentzians varied from 0.44 deg. to 0.90 deg. and was apparently uncorrelated with composition. X-ray (211) pole figure measurements revealed a high degree of twinning of the (100) bcc Fe{sub 100-x}Co{sub x} consistent with a recent study of Fe films electrodeposited on n-GaAs.