Aqueous Solution In The Electrochemical Preparation Of Sm-co Film Studies

With excellent magnetic properties such as very high Curie temperatures, high coercivity, and high saturation magnetizations, Sm-Co alloy films have promising application prospect in high-density magnetic recording media, electronic devices and Micro-Electro-Mechanical Systems (MEMS). The thesis mainly discusses the electrochemical behaviors of Sm3+ ion and Co2+ ion in chloride and sulfamate electrolyte systems. Sm-Co films were prepared in the both electrolyte systems at room temperature through constant potential technique. The thesis primarily researched the following contents:1. The codeposition of Sm3+ ion and Co2+ ion in the chloride electrolyte systems is researched. The cyclic voltammetry curve and EDS test of the deposited film show that Sm3+ ion and Co2+ion can realize the induced codeposition in this system. With potentiostatic electrodeposition method, Sm-Co films were fabricated on the copper substrates from the aqueous chloride electrolyte. The morphology, composition and structure of the deposited films were investigated by SEM, EDS and XRD, respectively. The results reveal that the films are silver gray, compact and uniform; The deposits consist of Sm, Co and a few impurity elements; The films are in amorphous state. Additionally, the effect of deposition potential on the film composition and morphology is studied. The results present that with deposition potential shifting to negative, the Sm relative content of deposits rises at first, and then decreases; the film morphology is gradually getting worse.2. The codeposition of Sm3+ ion and Co2+ ion in the sulfamate electrolyte systems is also investigated. The cyclic voltammetry curve and EDS test of the deposited film show that Sm3+ ion and Co2+ ion can realize the induced codeposition in this system. With potentiostatic technique, Sm-Co films were fabricated on the different substrates from the aqueous sulfamate electrolyte. The morphology, composition and structure of the deposits were characterized by SEM, EDS and XRD, respectively. The results reveal that the films are silver gray, compact and uniform; The deposits consist of Sm, Co and a few impurity elements; The films are in amorphous state. Compared with the chloride electrolyte, the sulfamate electrolyte is in favour of getting the high Sm content of the deposits. Additionally, the effect of deposition potential on the film composition and morphology is also studied. The results present that during lower potential range, with deposition potential shifting to negative, the Sm relative content of deposits presents a rising trend; compared with Cu substrates, the morphology prepared on the glass and silicon wafers is better.3. The effect of heat treatment on the structure, morphology and magnetic property of the deposits (Si slice substrate) is also under research. The results indicate that after heat treatment the film is in crystalline state, more compact and represents enhanced magnetism. And the precipitated crystal grains are detected.