Characteristics of Ni6Fe94 films deposited on SiO2/Si(100) by an oblique target co-sputtering

Abstract

Ni6Fe94 films were deposited on SiO2/Si(100) substrates at room temperature by oblique target co-sputtering and then annealed in vacuum at 573 K, 673 K and 753 K for 1 h, respectively. The as-deposited and annealed films mainly have a body-centered cubic structure and a [110]-crystalline orientation in the film growth direction. The [110]-orientation of the film enhances with increasing annealing temperature. A face-centered cubic phase coexists in the body-centered cubic phase of the Ni6Fe94 films annealed at 673 K and 753 K. The as-deposited film grows with thin columnar grains and has a void network at the grain boundaries. The grain size does not change markedly with annealing temperature, whereas the voids decrease with increasing annealing temperature. Furthermore, wide and short void network is formed upon annealing. The resistivity of the film decreases with annealing temperature. The temperature coefficient of resistance of the film annealed at 753 K is larger than that of the as-deposited film. The as-deposited film shows a hard magnetization requiring a saturation field of 3.34×105 A/m. The film annealed at 753 K shows an easy magnetization characteristic and its coercivity is 2.51×104 A/m. The saturation magnetization of the film increases with annealing temperature. The as-deposited and annealed films have an isotropic magnetization characteristic.