Preparation method of high-strength and high-stability vanadium oxide electronic phase change composite ceramic

Abstract

The invention belongs to the fields of metal functional semiconductor oxides, sensitive resistance materials and devices, electronic ceramics and the like, and particularly relates to a technical method for realizing coherent sintering of an oxide composite phase and vanadium oxide crystal grains through a rapid heat treatment process. The method is characterized by comprising the following steps: adding a certain proportion of an oxide composite phase with a crystal structure and lattice parameters similar to those of vanadium oxide powder into the vanadium oxide powder, and carrying out a high-energy-scale heat treatment process to realize coherent sintering between vanadium oxide parent grains and composite phase oxides, therefore, the mechanical strength, the electronic phase change function stability, the fatigue resistance and the thermal shock resistance of the vanadium oxide electronic phase change material are greatly improved. Sensitive components such as a sudden change type thermistor and a pressure sensitive resistor which are further prepared from the composite vanadium oxide electronic phase change material have higher electronic phase change function stability, mechanical property, ageing resistance and thermal shock resistance, and the service life of the sensitive components is remarkably prolonged in extreme environments such as low temperature, high pressure and high radiation.

Description

technical field [0001] The invention belongs to the fields of metal functional semiconductor oxides, sensitive resistance materials and devices, electronic ceramics and the like, and in particular relates to a method for realizing coherent sintering and space bridging of oxide composite phases and vanadium oxide crystal grains through a rapid heat treatment process, thereby greatly reducing the Technical methods for improving the mechanical strength, electronic phase change functional stability, fatigue resistance and thermal shock resistance of vanadium oxide electronic phase change materials. Background technique [0002] Vanadium dioxide (VO 2 ) is a classical metal-insulator transition (MIT) strongly correlated electron oxide with temperature-induced phase transition properties, that is, at the metal-insulator transition temperature (T MIT ) above is the metal phase with rutile structure, at T MIT The following is an insulating phase with a monoclinic structure [Scienc...

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Problems solved by technology

[0003]Although the phase change characteristics of VO2 have considerable application prospects in the fields of sensitive resistance devices, but VO2Materials have poor electronic phase transition function stability, low mechanical strength, insufficient fatigue resistance and thermal shock resistance, etc., which have always been a core difficulty in this field

These mechanical stresses will inevitably lead to the formation of microcracks and other defects at the grain boundaries of VO2 electronic ceramic materials, making it difficult to maintain a stable structural state when the phase transition occurs, and also reduce the VO 2Material mechanical strength and electronic phase transition functional stability

[0004] To sum up, at present, the biggest difficulty restricting the application of vanadium oxide electronic phase change materials in discrete sensitive resistance devices is that the materials accompanying electronic phase change Changes in the crystal structure can easily produce defects such as microcracks in the vanadium oxide ceramic material, which gradually reduces the mechanical properties of the material during use, increases the basic resistance of the material, and at the same time reduces the rate of change in resistivity triggered by its electronic phase transition

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