非晶合金Fe_(73.5-x)Cr_xSi_(13.5)B_9Nb_3Au_1(x=0,3,5)的临界现象

Critical behaviors of the Fe_(73.5-x)Cr_xSi_(13.5)B_9Nb_3Au_1(x=0,3,5) amorphous alloys ribbon

利用修正Arrott图方法研究了类Finemet的非晶合金Fe73.5-xCrxSi13.5B9Nb3Au1(x=0,3,5)的居里温度TC和铁磁-顺磁相变临界指数β,γ和δ.研究显示:所有样品的居里温度和临界指数都能很好地满足临界领域的磁性状态方程;随着Cr掺量的增加,居里温度逐渐减小;临界指数β和δ值的变化显示,相变类型从短程相互作用的3D海森堡模型逐渐变为长程相互作用的平均场模型.上述结果说明,Cr掺杂使得非晶合金Fe73.5-xCrxSi13.5B9Nb3Au1减弱了磁相互作用强度,同时扩展了磁相互作用力程.

According to modified Arrott plot method, we analyzed both Curie temperature and ferromagnetic- paramagnetic phase transition critical exponents fl, T and 3 of the Finemet-like amorphous alloys Fe（73.5-x）CrxSi（13.5）B9Nb3Au1（x=0,3,5）. Research shows all critical exponents of samples satisfied magnetic equation of state in the critical region. The results revealed that the Curie temperature is decreasing with increasing of doping amounts of Chromium. From the change of theβ and δ, it is further found that the type of phase transition changed from short-range 3D Heisenberg model to long range mean-field model, which indicated that doping Chromium to the amorphous alloys weakened the magnetic interaction intensities as well as expanded the magnetic interaction range.