THE EFFECT OF ANNEALING ON THE STRUCTURE OF GE20TE80 GLASS - ATOMIC-SCALE IMAGING USING A SCANNING TUNNELING MICROSCOPE

The effect of annealing on the structure of Ge20Te80 glass has been examined in atomic-scale images obtained using a scanning tunnelling microscope (STM). The STM image has been able in part to answer the question as to how the atomic structure is changed by low-temperature (< T(g)) annealing, whereas the effect of annealing on the structure was never observed in previous neutron diffraction study. Scanning tunneling microscope images as large as approximately 100 nm2 have provided atomic-resolution ridges approximately 3 nm in length. The nearest neighbour distance between peaks in each alignment is equal to approximately 0.5 nm; the alignments in parallel with each other are a distance of approximately 0.7 nm apart. These ridges can generate a surface associated with pseudo flatness, the size of which is less than approximately 10 nm2. Thus, the effect of annealing on the structure of as-quenched Ge20Te80 glass has given rise to intermediate-range order in a region less than approximately 10 nm2. The atomic configuration of annealed Ge20Te80 glass is inhomogeneous in the range < 10 nm2.