Electrodeposition conditions-dependent crystal structure, morphology and electronic properties of Bi films

[摘要] The study is devoted to the electronic properties and structure of bismuth films obtained by electrodeposition from high-speed perchlorate electrolyte. Polycrystalline samples were synthesized in acidic perchlorate electrolyte under the (0.18-70.0) mA/cm(2) cathode current density and annealed at 265 degrees C in the He gas atmosphere. The structure, microstructure and electron properties of Bi films were characterized using X-Ray diffraction analysis, scanning electron microscopy, and electron backscattered diffraction. Electrical resistance, magnetoresistance, and Hall coefficient were studied at the 5-300 K temperature range under magnetic field up to 8 T. A specific and unexpected behavior has been found concerning the average size and shape of Bi grains with increasing of the current density: the increase in deposition current density up to 70.0 mA/cm(2) contributes to Bi films formation with more isotropic and reduced average grains size. Samples synthesized under 0.18 mA/cm(2) current density after annealing showed electronic properties, including magnetoresistance, similar to those of flawless single-crystals. The differences in the electronic characteristics of Bi films electrodeposited under different currents and electrolyte composition were explained by changes in electronic mobility due to scattering on grain boundaries. (C) 2021 Elsevier B.V. All rights reserved.

[发布日期] 2021-12-20

[关键词] Bismuth;Electrodeposition;Perchlorate electrolyte;Microstructure;Structure;Electronic properties