Studies On The Electrochemical Properties And Alloy Films Preparation Of Rare Earth Ions [Sm(Ⅲ)、Tm(Ⅲ)、Ce(Ⅲ)] In Organic Solvents

Rare earth elements because of its unique excellent properties and wide applications, thus has caused widespread concern in the world of science and national technical field, known as the strategic elements in twenty-first century, current rare earth alloys and compounds has become an indispensable special materials advanced science and technology. Study on electrochemical properties in nonaqueous organic solvent systems has occupied more and more important position, especially in the preparation of electrodeposition lively rare earth metals and rare earth alloy films. Thorough study on rare earth elements in nonaqueous organic solvent systems of electrochemical properties and electrodeposition synthesis of rare earth alloy films, not only has the academic research value, but also has wide practical prospect, helps people to further on the deep understanding and knowledge of the electrochemical deposition of rare earth alloy films in nonaqueous organic solvent systems, improves this electrochemical deposition method of rare earth alloy films in nonaqueous organic solvent systems development and utility.This paper is in nonaqueous organic solvent systems were studied rare earth ions Sm(III),Tm(III), Ce(III) and iron series ion Ni(II) of the electrochemical properties, rare earth-iron series alloy films of Sm-Ni-Co and Ce-Ni-B by potentiostatic electrodeposition method, and alloy films were characterized by observation and analysis. Experiments chosen for the low toxicity of organic solvents dimethylformamide, and try to use non-toxic and pollution-free organic solvents anhydrous ethanol to study the electrochemical properties of the rare earth ions and alloy films.1. Application of LK2005 type electrochemical workstation, at room temperature under293 K, the electrochemical properties of Sm(III), Tm(III), Ce(III) and iron series ion Ni(II) are studied by cyclicvoltammetry and chronoamperometry and chronocoulometric methods and tafel methods. The research of Sm(III) on Pt electrode in dimethylformamide are studied in the reduction process is step irreversible reaction. The charge transfer coefficients is 0.0289 and the diffusion coefficients is 1.2875×10-5cm2/s, the exchange current density is 1.5961×10-6A/cm2.The electrochemical properties of Tm(III) on Cu electrode are studied by cyclicvoltammetry and chronoamperometry and chronocoulometric methods in dimethylformamide, the research of Tm(III) on Cu electrode are studied in the reduction process is not reversible. The transfer coefficients is 0.02836 and the diffusion coefficients respectively is 2.2439×10-5cm2/s and2.1954×10-5cm2/s and 2.1110×10-5cm2/s. The exchange current density is 1.3526×10-6A/cm2. Theelectrochemical properties of Ce(III) on Pt electrode are studied by cyclicvoltammetry and chronoamperometry in anhydrous ethanol, the charge transfer coefficients is 0.04584 and the diffusion coefficients respectively is 2.1169×10-6cm2/s and 2.2517×10-6cm2/s, the exchange current density is 9.5911×10-6A/cm2. The electrochemical properties of Ni(II) on Pt electrode are studied by cyclicvoltammetry and chronoamperometry in anhydrous ethanol, the charge transfer coefficients is 0.09188 and the diffusion coefficients respectively is 2.0533×10-5cm2/s and1.9702×10-5cm2/s, the exchange current density is 6.3535×10-5A/cm2. The research of Ce(III)and Ni(II) on Pt electrode are studied in the reduction process is step irreversible reaction.2. Study of rare earth ions Sm(III), Tm(III), Ce(III) and iron series ion Ni(II) of ion nucleation mechanism, the results show that Sm(III) on Pt electrode and Tm(III) on Cu electrode is obeys the mechanism of continuous nucleation and three dimensional growth in dimethylformamide, and Ce(III) on Pt electrode is obeys the mechanism of continuous nucleation and three dimensional growth in anhydrous ethanol, but Ni(II) on Pt electrode is obeys the mechanism of instantaneous nucleation and three dimensional growth in anhydrous ethanol.3. By potentiostatic electrodeposition method preparation of rare earth-iron series alloy films of Sm-Ni-Co and Ce-Ni-B, and by scanning electron microscopy(SEM) and X-ray energy dispersive spectrometer(EDS) to observe the surface structure and composition analysis of alloy films, observation and analysis of the results showed that: Metallic luster, good adhesion,uniform surface and density Sm-Ni-Co alloy film, the structure and performance are improved of compared with the Ni-Co alloy film. Metallic luster, uniform surface, density, good adhesion and the black Ce-Ni-B alloy film, the mass fraction of Ce and Ni in deposited film reaches to 2.63%,75.26%.