退火及成分对Co-C纳米复合薄膜磁性能的影响

摘要

Co-C nanocomposite thin films with Co contents of 13.0%-24.6 at% were deposited by magnetron sputtering.Co-C thin films were annealed at 400℃ for 2h in vacuum.Magnetic hysteresis loops of the as-deposited and annealed samples were measured at 5,77 and 300K.Annealing and composition dependence of microstructure and magnetic properties of Co-C nanocomposite thin films were investigated systematically.The as-deposited thin films show weak magnetization.Magnetic properties get enhanced after annealing.Samples with low Co content exhibit ferromagnetic properties at low temperature while superparamagnetic properties at room temperature,which is characteristic granular nature.Magnetization and coercivity,associated with the blocking temperature of Co-C thin films increase with increasing Co content.%用磁控溅射方法制备了Co含量介于13.0%～24.6%（原子分数）的Co-C纳米复合薄膜,在真空下对薄膜进行退火处理。测试了样品在5、77和300K下的磁化曲线,详细研究了退火及成分对薄膜微结构和磁性能的影响。结果表明未经退火的样品磁性较弱,退火之后样品磁性能增强,低Co含量的薄膜经退火后呈现出低温铁磁性、室温超顺磁性的颗粒薄膜特征。随着Co含量增加,薄膜的磁化强度和矫顽力均明显增大,冻结温度也随之升高。