Novel methods for the fabrication of ferromagnetic nickel and nickel boride thin films
Metal‐rich nickel boride thin films fabricated from boron‐containing precursor compounds by a cluster deposition process are shown to be ferromagnetic. The metal‐rich films fabricated by this approach exhibit hysteresis curves similar to those obtained for pure nickel foils. These films are a mixture of pure nickel and the Ni3B nickel boride phases. It is postulated that the hysteresis curves with smaller remnant magnetizations obtained from these films are a consequence of Ni3B inclusions within the films. Other novel organometallic source compounds for nickel chemical‐vapor deposition are briefly reviewed.
NMR and magnetic susceptibility study of rapidly quenched Ni100-XPX metallic glasses☆
Abstract In order to investigate the electronic structure of the rapidly quenched Ni100-XPX metallic glass system (18 ≦ x ≦ 22), NMR and magnetic susceptibility measurements have been carried out for temperatures 4.2 °K ≦ T ≦ 295 °K and magnetic fields H ≦ 20 kOe. The 31P Knight shift and relaxation rate behavior demonstrate a metalloid concentration dependence which is consistent with earlier work on the ternary NiPdP and NiPtP metallic glass systems. A consideration of the trends in the magnetic susceptibility indicates that, relative to the Fermi energy, the d-states associated with Ni are higher (the number of d-holes are greater) than those for Pd or Pt.
Magnetic properties of amorphous Ni-B alloys
Results of magnetization measurements carried out on rapidly quenched amorphous Ni 1-x B x alloys in the temperature range from 4.2 to 300 K in fields up to 15 kOe are presented and discussed. For the alloys with x=0.308,0.34, and 0.37, the magnetic susceptibility is found to comprise two contributions: a nonmagnetic contribution arising from the Pauli spin paramagnetism and a magnetic contribution resulting from trace iron impurities and giant nickel moments. The density of states at the Fermi level, N(E F ), evaluated from the temperature-independent part of the Pauli paramagnetic contribution, is found to vary linearly with the d-band occupation. By contrast, the amorphous Ni 81.6 B 18.4 alloy exhibits a magnetic behavior which can be completely accounted for in terms of a theory developed for very weak itinerant ferromagnets. Moreover, a comparison of the magnetic properties of this alloy with those observed for other weak itinerant crystalline ferromagnets strongly suggests an Invar-like behavior for the alloy in question.