Epitaxial NiMnSb thin films prepared by facing targets sputtering

We have prepared high-quality epitaxial NiMnSb thin films by facing targets sputtering (FTS), using an MgO monocrystalline substrate with an Mo-buffer layer. The epitaxial growth relation has been found to be (100)NiMnSb para llel to(100)Mo parallel to(110)MgO. Optimum deposition conditions have been determined to achieve highly ordered, continuous films with low rms roughn ess. The magnetic and transport properties of these films are comparable to that of bulk single crystals and are found to be independent thickness in the range 100-1000 Angstrom. The residual resistivity in particular (rho = 5.3 mu Omega cm for a 1000 Angstrom films) is much lower than what has been reported so far in the literature. All these features should ensure a high degree of spin polarisation and a minimum spin-flip scattering in multilay ered structures, thus enabling the use of these films for high-quality TMR/ GMR devices fabrication. (C) 2000 Elsevier Science B.V. All rights reserved .