EPITAXIAL-GROWTH, STRUCTURE AND PROPERTIES OF NI FILMS GROWN ON MGO(100) BY DC BIAS SPUTTER-DEPOSITION

Ni films of 70-240 nm thickness were deposited on an MgO(100) substrat e at temperatures T(s) greater-than-or-equal-to 190-degrees-C by d.c. sputtering at 2.5 kV in pure Ar gas. A negative bias voltage V(s) betw een zero and -110 V was applied to the substrate during the deposition . Reflection high energy electron diffraction, X-ray diffraction, cros s-sectional transmission electron microscopy, Auger electron spectrosc opy, ferromagnetic resonance and the measurement of the temperature co efficient of resistance were used to determine the structure and prope rties of the films. The degree of epitaxy of Ni increases with increas ing T(s) as well as increasing V(s). The optimum conditions for epitax ial growth of Ni are T(s) greater-than-or-equal-to 280-degrees-C and V (s) greater-than-or-equal-to 80 V. In this range epitaxial films with Ni(100) parallel-to MgO(100) and Ni[100] parallel-to MgO[100] can be p repared. A magnetic anisotropy is induced in the film plane. This anis otropy may be a result of superposition of a magnetocrystalline anisot ropy originating from the epitaxial Ni film and of a uniaxial magnetic anisotropy induced during the film formation. In conclusion, as V(s) ranges - 80 to - 110 V the bombarding effect of both energetic ions an d fast neutrals of Ar will rule the epitaxial growth of the Ni film by increasing the mobility of Ni adatoms and by resputtering the impurit ies. This effect is pronounced at T(s) greater-than-or-equal-to 280-de grees-C.