Thermally induced crystallization of amorphous Ge 0.4Se 0.6

Abstract

The Raman scattering measurement in amorphous Ge 0.4Se 0.6 was carried out at several temperatures below 440°C in order to investigate the relation in short range order between amorphous and crystalline phases. Raman spectra were obtained using 514.5 nm argon-ion laser and a double grating monochrometer. The 175 and 280 cm −1 vibrational modes in amorphous Ge 0.4Se 0.6 disappear after the complete crustallization, indicating that the chemical order including Ge-Ge bonds is characteristic to the amorphous phase but not to the crystalline one. This agrees with theresult by previous radial distribution studies that amorphous Ge xSe 1−x alloys with x > 1 3 have a different local order from the crystalline form. The A 1 mode peak of GeSe 4 tetrahedron units alters its position on heating. Therefore, it may be considered that intra- and inter-molecular interactions of this unit change through the crystallization process.