Efeitos das condições de deposição na microestrutura e nas propriedades supercondutoras de filmes finos de estanho obtidos por evaporação térmica convencional

Abstract

Superconductivity is a prominent area of condensed matter physics. The unique properties of superconductors have inspired over a century of studies and research, five Nobel Prizes, and applications in various practical contexts. In particular, superconducting thin films hold great potential for developing electronic devices, including quantum computing. This work presents a brief study on the influence of varying certain parameters of conventional thermal evaporation deposition, such as substrate temperature and the presence or absence of a thin initial layer (buffer) of germanium, on the structural and superconducting properties of tin thin films. For this purpose, the X-ray diffraction (XRD) technique was used to identify the crystalline structure of the tin films, while Scanning Electron Microscopy (SEM) examined the surface morphology of the samples, and the Magneto-Optical Imaging (MOI) technique for the magnetic characterization of the superconducting films. Although variations in growth conditions caused changes in the microstructure of the specimens, all tin films were found to be in the β (beta) allotropic phase, and they are all possibly superconductors. The microstructure was mainly affected by the change in substrate temperature, allowing the observation of flux avalanches at a temperature of 0.8 Tc, the superconducting critical temperature. Thus, the structural and magnetic characterization of the tin thin films facilitated the correlation of their superconducting properties with the deposition conditions.