Direct observations of Ge2Sb2Te5 recording marks in the phase-change disk

Abstract

Atomistic structures of the Ge2Sb2Te5 thin film in the real phase-change disk have been investigated using transmission electron microscopy (TEM). As-deposited amorphous Ge2Sb2Te5 films were laser-irradiated for initialization (crystallization) and recording. Cross-sectional TEM observations revealed that the recording mark was fully amorphized by laser irradiation. A slight difference between the as-deposited and the laser irradiation-induced amorphous Ge2Sb2Te5 was observed in the intensity profile of nanobeam electron diffraction patterns and atomic pair distribution functions. This difference was attributed to structural relaxation of amorphous Ge2Sb2Te5, which gives rise to the alteration of chemical order.

Stimulated crystallization of melt-quenched Ge2Sb2Te5 films employing femtosecond laser double pulses

“…One has to keep in mind that those results were obtained in as-grown amorphous material, as opposed to our conditions of melt-quenched amorphous material. Many studies have provided evidence of important differences in the crystallization behaviour 18,19 and the amorphous structure 24,25 of melt-quenched and as-grown films. We therefore interpret our measured lifetime value (s % 100 ps) as an effective carrier lifetime in fs-laser melt-quenched Ge 2 Sb 2 Te 5 films at relatively high fluences (F P2 ¼ 17 mJ/cm 2 ).…”

Structural fingerprints of electronic change in the phase-change-material: Ge2Sb2Te5

“…These results are similar to other simulations 1 and also experimental results. 4 The electronic structure is analyzed through the electronic density of states ͑EDOS͒ obtained from Hartree-Fock ͑HF͒ calculations. HF is used only to analyze the EDOS, not for forces and total energies.…”

Structural characterization and optical properties of pulsed laser deposition of Se75Te25 and Se75Te17Ge8 amorphous thin films

“…Thin film materials based on chalcogenide glasses have been recognized of their potential applications in different fields that encompass optical memory, fiber optics, and device for data storage as well as non volatile electronic storage [1][2][3][4][5]. It should be notice however, that such materials endorse an amorphous-crystalline phase transition with electrical switching property which constitute an advantageous features suitable for various industrial applications [1].…”