纳米Fe-ZnSe颗粒膜的结构与磁性

STRUCTURE AND MAGNETIC PROPERTY OF NANOMETRIC Fe-ZnSe GRANULAR FILMS

采用射频溅射法制备了纳米铁磁金属-半导体基体Fe_(0.35)(ZnSe)_(0.65)颗粒膜,并研究了其结构和磁特性.根据颗粒膜低场磁化率x(F)温度关系和不同温度下的磁滞回线,证实了在一定的温度范围内,颗粒膜中的纳米铁颗粒表现出磁性弛豫效应.当截止温度T_B=50 K时,颗粒膜的磁性由超顺磁性转变为铁磁性.在截止温度以上,其饱和磁化强度M_S(T)温度关系符合Bloch的自旋波T^(3/2)定律,探讨分析了自旋波常数增大的原因.

Nanometer granular film of ferromagnetic metal-semiconductor matrix, Feo.35（ZnSe）0.65 （volume fraction）, was fabricated by the radio frequency sputtering, and the structure and magnetic property of the film have been studied. According to the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it was found that the nanometer-sized Fe particles in granular films showed the magnetic relaxation effect at definite temperature. The magnetic property of granular film changes from super-paramagnetic into ferromagnetic at the blocking temperature TB=50 K. Above TB the MS（T） of the granular films follows the Bloch＇s spin wave T^3/2 law. The causes of increase of the spin wave constant are explored and analyzed.