EFFECTS OF HIGH MAGNETIC FIELD ON THE STRUCTURAL EVOLUTION AND MAGNETIC PROPERTIES OF NANOCRYSTALLINE Ni FILMS

This paper studies the effects of a high magnetic field on the structural evolution and magnetic properties of nanocrystalline Ni films prepared on quartz substrates by a molecular beam vapor deposition (MBVD) method. Atomic force microscope, X-ray diffractometer, transmission electron microscope and vibrating sample magnetometer were used to study the microstructures and magnetic properties of the Ni films. The results indicate that high magnetic field has no obvious influence on crystal structures except changing the lattice constant of the Ni films. However, the high magnetic field can re fine particle size. The film deposited under magnetic field tends to grow through columnar mode because of the magnetized particles aligning along the direction of magnetic field. Furthermore, the ordered and dense arrangement of Ni atoms results in more spins contained in per unit volume and improves the saturation magnetization (Ms). Ms of the 6T Ni film increases by 70% (578 emu/cm(3)) than that of the film without magnetic field (341 emu/cm(3)), and the coercivity is also slightly increased for the 6T film.