Appearance of ferromagnetism by crystallizing a-Ge1−xMnxTe film

The fabrication of ferromagnetic fine patterns in the a-Ge1−xMnxTe films by using the phase change has been reported. Amorphous Ge1−xMnxTe films are prepared by conventional RF sputtering method at room temperature. After deposition, amorphous films are crystallized by annealing at various temperatures 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 View the MathML source increases in proportion to the applied magnetic field, that is paramagnetic. On the other hand, hysteresis is observed in the magnetization curve of annealed film, which means that the ferromagnetic fine pattern can be formed in an amorphous matrix by crystallization. Ferromagnetic wire patterns having View the MathML source 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 magnetoresistance is also obtained in these patterns.