Assembly of submicrometre ferromagnets in gallium arsenide semiconductors
Assembly of submicrometre ferromagnets in gallium arsenide semiconductors
复制标题
砷化镓半导体中亚微米铁磁体的组装
作者：
Jing Shi;J. M. Kikkawa;R. Proksch;T. Schäffer;D. Awschalom;G. Medeiros;Pierre Petroff
磁性多层膜1和颗粒固体2，3中自旋相关电子现象的发现为低维磁性系统中自旋相互作用的性质提供了有价值的见解，并为基于这些现象的新技术开辟了道路。在半导体的情况下，微观磁体的结合将允许基于半导体的量子结构的电子灵活性与局部磁性相结合，从而有可能开发新的可调谐自旋相关的磁电子和磁光器件。最近尝试将铁磁性引入IIIV族化合物半导体中，涉及原子薄层的外延生长，产生二维磁性膜5而不是局部磁性结构。在这里，我们描述了一个简单的方法，用于制造分立的微观铁磁体在IIIV半导体砷化镓。半导体首先被均匀地注入锰离子。随后的热处理导致显著的相分离，从而亚微米晶体的GaMn成核和生长从注入层。由此产生的粒子是铁磁性的，居里温度超过室温。
THE discovery of spin-dependent electronic phenomena in magnetic multilayers1 and granular solids2,3 has provided valuable insights into the nature of spin interactions in low-dimensional magnetic systems, and has opened the way to new technologies based on these phenomena. In the case of semiconductors, the incorporation of microscopic magnets would allow the electronic flexibility of semiconductor-based quantum structures to be combined with local magnetism4, potentially enabling the development of new tunable spin-dependent magneto-electronic and magneto-optical devices. Recent attempts to introduce ferromagnetism into IIIV compound semiconductors have involved epitaxial growth of atomically thin layers, yielding two-dimensional magnetic films5 rather than localized magnetic structures. Here we describe a simple approach for fabricating discrete microscopic ferromagnets in the IIIV semiconductor gallium arsenide. The semiconductor is first uniformly implanted with manganese ions. Subsequent heat treatment leads to a striking phase separation, whereby submicrometre crystals of GaMn nucleate and grow from the implanted layer. The resulting particles are ferromagnetic, with Curie temperatures exceeding room temperature.