Temperature dependence of electrical resistance in Ge-Sb-Te thin films

J.L.GARCIA; M.A. UREÑA; M. FONTANA; B. ARCONDO

Cluj-Napoca

Conferencia; 7 International Conference Amorphous and Nanostructured Chalcogenides (ANC 7); 2015

Nowadays, the GeSbTe system is extensively studied for use in the field of both electrical and optical non-volatile memories. The key of this application is based on the changes in the physical properties (electrical conductivity or refractive index) of these films as the product of structural transformation between amorphous or crystalline state. Both states are highly stable and it is relative easy to change between them when they are prepared as thin film. In this work, the structure and the electrical behaviour of thin films with compositions Ge13Sb5Te82, Ge1Sb2Te4, Ge2Sb2Te5 and Ge1Sb4Te7 are presented. The films obtained by pulsed laser deposition (PLD) using a pulsed Nd: YAG laser (λ = 355 nm) were structurally characterized by X-ray diffraction. The temperature dependence of the films electrical resistance was studied from room temperature to 520 K with several heating rates (2 - 10 K / min). During crystallization, the electrical resistance of the film falls several orders of magnitude in a narrow temperature range. The electrical conduction activation energies of the amorphous and crystalline states and the crystallization temperature were determined. The crystallization products were characterized by X-ray diffraction. Results are compared with those obtained by other authors.