Magnetic Properties and Structure of Fe-based Amorphous Alloys

研究了铁基非晶合金的强场磁化、交流磁化率、磁冷却、硬度、线性磁致伸缩、强迫体积磁致伸缩、热膨胀、弹性性能、中短程有序结构和穆斯堡尔效应。主要结果如下：1）由交流磁化率、磁冷却效应和微分磁化率确定的受迫体积磁致伸缩的温度依赖性在自旋冻结温度处出现峰值; 2）线性磁致伸缩的温度依赖性在低温下表现出明显的热滞效应。这种行为与sin玻璃态的弛豫密切相关。3）居里温度以下硬度的陡峭温度依赖性是由大的自发体积磁致伸缩引起的。4）非晶态合金的磁性对结构变化如配位数和原子间距非常敏感。5）在自旋冻结温度以下，由于横向分量的冻结，内磁场的温度依赖性表现出明显的增加。6）外推Fe-13的同质异能移，发现Fe-13的同质异能移随温度的升高而增大。基合金对纯非晶铁的还原能力非常接近UPSILON-Fe的值。合金的四重溅射率约为0.4，为非晶态结构。

High-field magnetization, AC Susceptibility, magnetic cooling, hardness, linear magnetostriction, forced-volume magnetostriction, thermal expansion, elastic properties, short- and medium-range order structure and Mossbauer effect in Fe-based amorphous alloys have been investigated. The main results are summarized as follows;1) The temperature dependence of the forced volume magnetostriction shows the peak at the spin freezing temperature determined from AC susceptibility, magnetic cooling effect and the differential susceptibility.2) The temperature dependence of the linear magnetostriction exhibits a remarkable thermal hysteresis at low temperatures. This behavior is closely correlated with the relaxation of the sin glass state.3) The steep temperature dependence of the hardness below the Curie temperature is caused by a large spontaneous volume magnetostriction.4) The magnetic properties of the amorphous alloys are very sensitive to the structure change such as the coordination number and the atomic distance.5) The temperature dependence of the internal magnetic field shows a distinct increase below the spin freezing temperature due to the freezing the transverse component.6) The extrapolation of the isomer shift of the Fe-based alloys to pure amorphous iron is very close to the value of UPSILON-Fe. The quadruple spulliting of these alloys is about 0.4, reflecting the amorphous structure.