【作者】 陈娜；

【Author】 Chen Na;Tsinghua University;

【机构】 清华大学材料学院；

【摘要】 磁性非晶合金作为一类兼具原子结构长程无序和磁长程有序的材料,为建立和发展非晶材料和自旋电子学及器件的交叉领域方向提供了独具特色的研究对象。通过在磁性非晶合金中引入氧诱发金属-半导体转变,可以制备出成分和结构连续可调的非晶材料,实现同一材料体系磁、光、电等性能连续可调的非晶态金属、半导体、绝缘体的精准制备,为理解和揭示非晶材料领域长期存在的结构-性能关系提供新的研究思路。通过热处理晶化诱发半导体-金属转变,可以使得磁性非晶半导体转变为磁性金属。晶化前后磁性非晶薄膜的电阻率变化可达约三个数量级,有可能成为一种室温磁性相变材料,在新型非易失相变存储器件中获得应用。更多还原

【Abstract】 Encompassing diverse behavior from metals to insulators, amorphous solids are useful in optics, electronics and catalysis. Local atomic configurations determine their electronic structure and properties, yet it poses a significant challenge to the experimental setup of a reliable structure-property correlation in amorphous materials. Here we demonstrate that a spectrum of behavior from magnetic metal to paramagnetic insulator is realized in one Co-Fe-Ta-B-O system via continuously compositional adjustability. Hence, the amorphous structure can be manipulated in a well controllable manner, leading to tunable optical, electrical and magnetic properties over a wide range. Particularly, the electric-field effect on the magnetism is obtained and varies significantly in the system. The combined optical, electrical and ferromagnetic functionalities in the amorphous system may assure them an important role in low-power-consumption electronic/spintronic devices. Furthermore, crystallization induces a semiconductor-metal transition in the amorphous ferromagnetic semiconductors based on ferromagnetic alloys. The significant resistance difference in their crystalline and amorphous states enables them to be room-temperature ferromagnetic phase change materials that could be used in new non-volatile phase change memories.更多还原