近零膨胀Zr0.5Hf0.5V1.4P0.6O7材料的制备及其性能研究

采用传统的固相法合成了近零膨胀氧化物功能陶瓷材料Zr_0.5Hf_0.5V_1.4P_0.6O₇,用X射线衍射(XRD)、Raman光谱和热膨胀法对Zr_0.5Hf_0.5V_1.4P_0.6O₇的热膨胀系数、各向同性和相变进行了测试,通过Hf⁴⁺/P⁵⁺共掺杂使得材料具有较低的热膨胀系数,研究发现合成的Zr_0.5Hf_0.5V_1.4P_0.6O₇具有Pa3立方相结构,从334 K附近到673 K较宽的温度范围内的线性热膨胀系数为-1.56×10^-6 K^-1,表现出稳定的近零热膨胀特性。由于固溶体内部微结构的影响造成膨胀仪实验结果与变温X射线衍射结果存在一定的差距。Zr_0.5Hf_0.5V_1.4P_0.6O₇具有的近零膨胀特性为通过负热膨胀材料合成膨胀系数可控的材料提供了基础。

Preparation and Properties of the Near Zero Thermal Expansion of Zr0.5Hf0.5V1.4P0.6O7

Near zero expansion oxide functional ceramics Zr_0.5Hf_0.5V_1.4P_0.6O₇ was synthesized by the traditional solid-state method and then the thermal expansion properties of the synthesized samples were explored.X-ray diffraction(XRD),Raman spectra and thermal dilatometry were used to investigate the coefficient of thermal expansion(CTE),isotropy and phase transition of Zr_0.5Hf_0.5V_1.4P_0.6O₇.Hf⁴⁺/P⁵⁺double ion doping results in the material has smaller coefficient of thermal expansion.The investigation results show that the samples are single cubic phase with the space group of Pa3 in the crystal structure.The linear expansion coefficient of Zr_0.5Hf_0.5V_1.4P_0.6O₇ is calculated to be-1.56×10^-6 K^-1 in the temperature range from 334 K to 673 K and has near-zero thermal expansion characteristic in a wide temperature range.Due to the influence of the internal microstructure of the solid solution,there is a certain gap between the expansion test results and the X-ray diffraction results at variable temperature.The near zero thermal expansion(NZTE)property of Zr_0.5Hf_0.5V_1.4P_0.6O₇ provides a basis for the synthesis of materials with controllable expansion coefficient of negative thermal expansion materials.