Investigation of possible giant magnetoresistance limiting mechanisms in epitaxial PtMnSb thin films

• Published in: Journal of applied physics 1997-04, Vol.81 (8), p.4026-4028
• Main Authors: Kautzky, M. C., Mancoff, F. B., Bobo, J.-F., Johnson, P. R., White, R. L., Clemens, B. M.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.364925

To investigate the possibility of using the half-metallic ferromagnet PtMnSb in giant magnetoresistance (GMR) applications, we have examined the surface roughness, structural uniformity, mean-free path, and lattice disorder of sputtered epitaxial PtMnSb(111) films on Al2O3(0001) in the range 85 Å⩽t⩽1100 Å. Atomic force microscopy revealed the films to be very flat, with an rms roughness of ≈3 Å for thicknesses below 100 Å. X-ray diffraction and vibrating sample magnetometry indicated that the entire volume of the single-phase films were ferromagnetic (Ms≈500 emu/cm3), with no evidence for a nonstoichiometric or oxidized surface layer. Hall-effect measurements and fits to resistivity versus thickness data by surface scattering models yielded mean-free-path values of 18.4 and 80–100 Å, respectively. Atomic site disorder was estimated at ≈10% from structure factor analysis of integrated x-ray peak intensities. These results suggest that bulk properties will play the largest role in determining the effectiveness of PtMnSb in GMR applications.