Density Functional Theory Analysis of the Electronic Properties of the Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub>

Garibova S. N., Aliyev M. E., Ashurova U. I., Suleymanova L. C., Kerimova A. M., Rza-yeva S. A., ...More

CHALCOGENIDE LETTERS, vol.22, no.12, pp.999-1008, 2025 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 22 Issue: 12
  • Publication Date: 2025
  • Doi Number: 10.15251/cl.2025.2212.999
  • Journal Name: CHALCOGENIDE LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.999-1008
  • Istanbul University Affiliated: Yes

Abstract

In this work, the electronic behavior of the chalcogenide semiconductor Ge(2)Sb(2)Te(5 )was examined using a first-principles computational approach. The study was carried out within the density functional theory framework, where the spin-polarized generalized gradient approximation was applied through the Atomistix ToolKit software. A double-zeta polarized basis set formed the foundation of the calculations, while exchange-correlation interactions were treated using the Perdew-Burke-Ernzerhof functional. Sampling of the Brillouin zone was performed according to the Monkhorst-Pack method with a 2 x 2 x 2 k-point grid, ensuring accuracy through special-point integration. Atomic configuration optimization, also conducted in Atomistix ToolKit, allowed the determination of the most energetically favorable arrangement for the Ge-Sb-Te lattice. Structural characteristics-including crystallite size and crystallinity-were evaluated using the Debye-Scherrer and Halder-Wagner analytical method. The relaxation of the unit cell revealed a marked redistribution of atoms, most notably between Ge and Te positions, resulting in higher symmetry and improved stability. Furthermore, the analysis indicated that distinct Ge-Sb-Te phases exhibit measurable differences in lattice constants, which in turn influence their physical performance. The refined structural model, characterized by enhanced symmetry and stability, provides a reliable representation of crystalline Ge2Sb2Te5, making it a valuable reference for phase-change memory technology development.