非晶态Fe_(90-x)Si_xZr_(10)合金的磁矩,Curie温度和自旋波激发

MAGNETIC MOMENT, CURIE TEMPERATURE AND SPIN WAVE EXCITATION FOR AMORPHOUS Fe_(90-x) Si_x Zr_(10) ALLOYS

非晶态Fe_(90-x)Si_xZr_(10)(x=0,4,7,10)合金是用单辊急冷方法制备的,用提拉样品磁强计测量了样品的磁化曲线和热磁曲线。发现每个磁性原子的平均磁矩μ和Curie温度T_c随Si含量的增加而增加,与相应的非晶态FeSiB合金相比,非晶态FeSiZr合金的μ和T_c明显偏低,认为这一反常现象是Fe-Fe原子间的反铁磁耦合的存在所致。低温下样品的磁化强度与温度的关系较好地符合Bloch T^(3/2)定律,得到自旋波劲度系数D从x=0时的0.37meV·um^2增加到x=10时的0.538meV·um^2,计算出交换相互作用范围都是在最近邻原子间的距离。

The magnetization curves at 1.5K and thermomagnetization curves forthe amorphous Fe_(90-x)Si_(x)Zr_(10) (x=0, 4,7 or 10) alloys prepared by the drum spinningtechnique bave been measured with an extracting sample magnetometer. It is obtain-ed that the average magnetic moment, μ, per magnetic atom and Curie temperature,T_c, in the amorphous FeSiZr alloys increase with increasing Si content. The μ andT_c are found to be quite small, compared with amorphous FeSiB alloys. This unu-sual behaviour is suggested to be due to the presence of the Fe-Fe antiferromagneticinteractions. The temperature dependence of magnetization at low temperature is inaccordance with Bloch T^(3/2) law. Calculation shows that the spin wave stiffnessconstant, D, increases with increasing Si conteat from 0.37 meV·nm^2 for x=0 to0.538 meV·nm^2 for x=10. The values of 〈r^2〉 indicate that the range of the exchangeinteraction is roughly the mean atomic distance of nearest neighbours.