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.
Low temperature specific heat and electrical resistivity of amorphous Ni–B alloys
The specific heat of Ni100−xBx amorphous alloys with x=18, 32, 36, and 40 is determined from 0.7 K to 40 K, and compared with results for Ni80P14B6 and Ni–P alloys. The electronic contribution (γT) decreases rapidly for the Ni–B alloys as the B concentration increases and as P replaces B near the Ni80M20 composition. The temperature dependence of the Debye temperature is obtained up to 40 K. For Ni82B18, the Debye temperature is in good agreement with the value obtained from the temperature dependence of the electrical resistivity (ρ/ρ300). (ρ/ρ300) was measured for all four alloys. The magnetic specific heat CM, which is almost temperature independent, is attributed to ferromagnetic clusters in these paramagnetic alloys.
Magnetic properties of Lu2Fe17 crystals
Abstract We present the results of crystal structure and magnetization studies of three single crystals grown from melts of different nominal compositions in the vicinity of the Lu2Fe17 stoichiometry. The ferromagnetic state of the crystals is strongly dependent on the real sample composition and the local atomic ordering. A drastic difference is observed in the behaviour of the ferro–antiferromagnetic transition, even in crystals for which almost identical composition and crystal parameters were determined by microprobe and X-ray analysis.