Structural, electric and kinetic parameters of ternary alloys of GeSbTe

Thin amorphous films of GeSbTe have been widely employed in the technology used for phase change optical memory or compact disks. In this article, we report on measurements of resistance, transmittance, and X-ray diffraction in thin films with stoichiometric compositions of Ge₁Sb ₄Te₇, Ge₁Sb₂Te₄, Ge ₂Sb₂Te₅, and Ge₄Sb ₁Te₅. The resistivity, lattice constant, and the temperature at which transformation from the amorphous phase to the cubic crystalline structure occurs were calculated for each stoichiometric composition, and the energy activation was determined, applying Kissinger's model. It was found that the Ge₄Sb₁Te₅ composition has the highest crystallization temperature (425 K), the highest resistivity (0.178 Ω cm), the greatest E_a (3.09 eV), and the lowest lattice constant (a=5.975 Å) in the cubic phase at 170°C.