Appearance of ferromagnetism by crystallizing a-Ge1-xMnxTe film

The fabrication of ferromagnetic fine patterns in the a-Ge1-xMnxTc films by using the phase change ha's been reported. Amorphous Ge1-xMnxTe films are prepared by conventional RF sputtering method at room temperature. After de position, amorphous films are crystallized by annealing at various temperat ures and basic properties of both the amorphous and crystalline phases are measured. It has been clarified that the electrical and optical properties of the crystalline phase are widely different from those of amorphous phase . The low-field-magnetization of an amorphous film at 4.2 K increases in pr oportion to the applied magnetic field, that is paramagnetic. On the other hand, hysteresis is observed in the magnetization curve of annealed film, w hich means that the ferromagnetic fine pattern can be formed in an amorphou s matrix by crystallization. Ferromagnetic wire patterns having 1 mum width are successfully formed in the a-Ge1-xMnxTe film by irradiating the laser beam. Hysteresis is observed in the magnetization curve of Ge1-xMnxTe film having the crystalline wires and the hysteretic behavior of negative magnet oresistance is also obtained in these patterns. (C) 2001 Elsevier Science B .V. All rights reserved.