ABSTRACT
H Asahi, Y K Zhou, M S Kim, S Emura, S Shanthi, S Kimura and S Hasegawa The Institute of Scientific and Industrial Research, Osaka University 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
Abstract. Transition-metal-and rare-earth-doped GaN were studied. GaCrN showed the ferromagnetic characteristics at 7-400K. Clear hysteresis and clear saturation were observed in the magnetization versus magnetic field (M-H) curves at all measuring temperatures. We observed the photoluminescence (PL) emission from GaCrN layers. For the GaCrN/GaN/GaCrN trilayer structures, hysteresis loop was observed in the magnetic field dependence of vertical electrical resistance. GaGdN also showed the ferromagnetic characteristics at 7^J00K. Sharp PL emission was observed from GaGdN. DyN/GaN superlattices were also studied and spin tunnel resistance characteristics were observed. 1
1. Introduction III-V-based diluted magnetic semiconductors (DMSs) have been gathering great interest from the industrial viewpoints because of their potential utility as new functional materials that lead to the introduction of spin degree-of-freedom into semiconductor devices. Magnetic semiconductors for practical applications require the following features. One is to have a Curie temperature (Tc) higher than room temperature, and second is to be based on a typical semiconductor in which the carrier control technique is well established. In this paper, we will describe the experimental results on the transitionmetal-doped GaN, GaCrN, the rare-earth-doped GaN, GaGdN and the DyN/GaN superlattices (SLs).
