Research on Simulation, Experiment and Evaluation Method of Different Ratio Gd Doped AgSnO₂ Contact Material

AgSnO 2 electrical contact material with greenery and good performance has the most potential to replace the toxic AgCdO. However, SnO 2 in AgSnO 2 contact material is a kind of semiconductor with wide band gap, which is almost insulated and has high hardness, resulting in the increase of contact resistance and temperature rise, and easy to form microcracks. First principle based on density functional theory are used to simulate three doping ratios (8.3%, 12.5%, 16.7%) of rare earth element Gd doped SnO 2 . The simulation results show that when the doping ratio is 12.5%, electrical performance is the best. As the doping ratio increases, the smaller the hardness, the higher the probability of microcracks. To more objectively obtain the doping ratio with the best comprehensive performance, the comprehensive evaluation model of Technique for Order Preference by Similarity to Ideal Solution with entropy weight is adopted to evaluate, and the performance with doping ratio of 12.5% is the best. Finally, it is verified by experiments. Different ratio of Gd doped SnO 2 powders are prepared by the sol-gel method, and the X-ray diffraction test proves that the sol-gel method can realize the substitution doped model established by simulation. The doped AgSnO 2 is prepared by powder metallurgy method, and its electrical performance and hardness are measured. The theory and experiment can be well matched, which proves the feasibility and credibility of simulation. It provides a new idea and scientific reference for the research on doping to improve the properties of AgSnO 2 contact material.