【摘要】 以脉冲激光沉积法沉积制备了立方相负热膨胀ZrW1.5Mo0.5O8薄膜并利用X射线衍射仪(XRD)和场发射扫描电镜对其结构组分、表面形貌和厚度进行表征。采用变温XRD分析了ZrW1.5Mo0.5O8靶材和薄膜的负热膨胀特性。实验结果表明:在1080℃烧结6h制备得的立方相ZrW1.5Mo0.5O8陶瓷靶材,靶材具有较高的纯度和良好的负热膨胀性能,Mo离子掺入后,其α到β相转变温度降低,在30~600℃温度区间内,ZrW1.5Mo0.5O8陶瓷靶材的负热膨胀系数为-7.13×10-6K-1。利用该靶材在500℃时脉冲激光沉积的ZrW1.5Mo0.5O8薄膜为非晶态,薄膜表面平滑致密,厚度约为835nm;非晶膜在1180℃热处理7min后淬火得到立方相ZrW1.5Mo0.5O8薄膜;结晶后的ZrW1.5Mo0.5O8薄膜为多晶膜。在室温到600℃区间内,立方相ZrW1.5Mo0.5O8薄膜的热膨胀系数为-7.7×10-6K-1,α-ZrW1.5Mo0.5O8到β-ZrW1.5Mo0.5O8的相转变温度降至100℃以下。更多还原

【Abstract】 The ZrW1.5Mo0.5O8 coatings were synthesized by pulsed laser deposition with a lab-made ZrW1.5Mo0.5O8 target.The impact of the synthesis conditions of both the target and coatings on the microstructures and negative thermal expansion was respectively investigated with X-ray diffraction and scanning electron microscope.The results show that the thermal expansion coefficient of the highly-pure cubic ZrW1.5Mo0.5O8 target,sintered at 1080℃for 6 h,is- 7.13 × 10- 6K- 1in 30 to 600℃ range,and that the Mo-doping reduces the α-β phase transition temperature.The smooth compact ZrW1.5Mo0.5O8 coatings,835 nm in thickness,were deposited at 500℃; and the annealing,at 1180℃ for 7 min in Pt-foil enclosed air,resulted in a transition from amorphous phase to polycrystalline cubic phase and an averaged thermal expansion coefficient of-7.7 × 10- 6K- 1in a range from room-temperature to600℃.Moreover,the α-β transition temperature of the coatings drops down to below 100℃.更多还原