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本文讨论在常温和29～207℃温区内用 X 射线衍射技术研究(V_(1-x)Cr_x)_2O_3陶瓷样品中的金属—绝缘体(M—I)相变。实验中发现,即使在低于相变点的室温下,样品中仍存在部分绝缘相。同时发现金属—绝缘体相变温区很宽。作者对此进行了分析讨论,认为导致上述现象的直接原因是材料的成分起伏和应力起伏。对M—I 相变的过程提出了假设模型,并在此基础上解释了陶瓷样品的 X 射线实验结果和阻温特性。
In this paper, the phase transition of metal-insulator (M-I) in (V_ (1-x) Cr_x) _2O_3 ceramics was investigated by X-ray diffraction at room temperature and in the temperature range of 29 ~ 207 ℃. It was found in the experiment that a part of the insulating phase still exists in the sample even at room temperature below the phase transition point. Also found that metal - insulator phase transition temperature is very wide. The author has carried on the analysis and discussion, thinks the direct reason that causes the above-mentioned phenomenon is the material composition fluctuation and the stress fluctuation. The hypothetical model of M-I phase transition was proposed, and on the basis of this, the X-ray experimental results and temperature-resistance characteristics of ceramic samples were explained.