Study of MnAs as a Spin Injector for GaAs-Based Semiconductor Heterostructures
- PDF / 375,618 Bytes
- 9 Pages / 439.37 x 666.142 pts Page_size
- 61 Downloads / 149 Views
Study of MnAs as a Spin Injector for GaAs-Based Semiconductor Heterostructures J. Kwon · R.E. Goacher · E.D. Fraser · L. Schweidenback · A.H. Russ · J.B. Hatch · A. Petrou · J.A. Gardella Jr. · H. Luo
Received: 31 May 2012 / Accepted: 27 July 2012 / Published online: 5 September 2012 © Springer Science+Business Media, LLC 2012
Abstract We report studies of two key factors involved in the use of MnAs as a spin injector, namely, Mn diffusion and spin injection properties when it is grown on GaAs-based semiconductor heterostructures. Depth profile of Mn concentration in a sample consisting of a MnAs film grown on GaAs is investigated with timeof-flight secondary ion mass spectroscopy. The result shows that Mn diffusion into GaAs is negligible, unlike the case of Ga1−x Mnx As/GaAs, in which Mn diffusion is significant. Meanwhile, robust spin injection is observed with MnAs as a spin injector for a GaAs-based light emitting diode, persisting up to room temperature. Keywords Spintronics · MnAs · Diffusion · ToF-SIMS · Spin-LED · Spin injection
1 Introduction Modern materials physics and engineering often involve integrating different materials and structures to realize new functionalities. Interfaces are therefore important J. Kwon · E.D. Fraser · L. Schweidenback · A.H. Russ · J.B. Hatch · A. Petrou · H. Luo () Department of Physics, The University at Buffalo, The State University of New York, Buffalo, NY 14260, USA e-mail: [email protected] R.E. Goacher · J.A. Gardella Jr. Department of Chemistry, The University at Buffalo, The State University of New York, Buffalo, NY 14260, USA Present address: R.E. Goacher Department of Chemistry, Biochemistry, and Physics, Niagara University, NY 14109, USA Present address: E.D. Fraser Intelligent Epitaxy Technology, Inc., 1250 E. Collins Blvd., Richardson, TX 75081, USA
378
J Low Temp Phys (2012) 169:377–385
Fig. 1 Schematic diagrams showing structures for producing charges (top) and spin polarization (bottom). The left hand side is where charges (spins) are generated (aligned), and the right hand side is where the charges (spin aligned electrons) are moved to for intended functions
parts of the structures, especially when dimensions are reduced. The quality of interfaces of various types has been an important topic for many materials systems. This is especially the case in semiconductor heterostructures incorporated in electronic devices, when currents often have to pass through interfaces for device functions. Sharp interfaces are almost always not thermodynamically stable configurations, although they can be metastable at temperatures involved in growth, processing and device operation. However, intermixing at the interface and interdiffusion between adjacent layers are common side effects and can have adverse consequences. Semiconductor spintronics is an area where integration of magnetic materials and semiconductors provides a mechanism for generating spin polarization in a nonmagnetic semiconductor. Spin polarized charge carriers can be injected in such cases from a ferr
Data Loading...
