【作者】 肖兆娟；

【导师】 程晓农；

【作者基本信息】 江苏大学 ， 材料学， 2006， 硕士

【摘要】 新型负热膨胀（Negative Thermal Expansion简称NTE）材料ZrW₂O₈具有负热膨胀系数大、各向同性且响应温度范围宽等特点，在电子学、光学、通信、医学、日常生活等方面具有广阔的应用前景。但是目前国际上研究较多的为粉体、块材，而对ZrW₂O₈薄膜材料的研究还鲜有报道。 本研究中，使用射频磁控溅射法制备ZrW₂O₈薄膜，所用靶材为ZrO₂和WO₃混合陶瓷靶。通过调节溅射气压、溅射气氛、后热处理温度及气氛等实验参数，以期获得纯度较高的ZrW₂O₈薄膜。实验中研究了不同溅射参数及热处理参数对薄膜物相、成分及形貌的影响。采用X射线衍射（XRD）、扫描电镜（SEM）、台阶仪、划痕仪等对薄膜物相、形貌、膜厚、结合力进行了研究。 试验结果表明：1号靶材（ZrO₂与WO₃的化学计量比为2：1）所制备的薄膜，在其它溅射参数保持一定的条件下，其厚度随着溅射气氛中氩气浓度的降低而变薄；膜厚与溅射时间近似成线性关系；薄膜的沉积速率与溅射功率近似呈线性关系；在一定的范围内，薄膜的附着力随着膜厚的增加先减小后增大。 利用XRD对薄膜进行物相分析，可知沉积态的薄膜为非晶态的。1号靶材制备的薄膜变温XRD的结果发现在720℃左右ZrW₂O₈薄膜的晶化效果最好。用RTP-300快速退火炉处理时，薄膜的最佳热处理温度为780℃。对2号靶材（ZrO₂与WO₃的化学计量比为1：2.8）所制备的薄膜用快速退火炉处理时，其最佳热处理温度为740℃。低于此温度处理时，ZrW₂O₈薄膜晶化不完全，高于此温度处理时，ZrW₂O₈薄膜发生分解。SEM观察可知热处理温度低于700℃时，薄膜的表面比较均匀，750℃左右时薄膜的结构最致密，当热处理温度高于1000℃时，薄膜发生了开裂。热处理时通氧对不同成分靶材所制薄膜的效果是一致的。通氧热处理后的薄膜的晶粒细化，生长更为致密。 热处理后，根据Scherrer公式计算的结果发现薄膜的晶粒尺寸随热处理温度的提高而减小。利用变温XRD的结果，试算了ZrW₂O₈结晶度较高的（221）、（220）和（321）三个向上的热膨胀系数，均为负值。且其值比粉体的膨胀系数要大。更多还原

【Abstract】 New negative thermal expansion （NTE） material ZrW₂O₈ was discovered to display unusual strong negative thermal expansion in a board temperature range. It has various applications in electronics, optics, biomedicine, sensor etc. But recently more powders and bulks were studied and less reports on films were seen in the international wide.Radio frequency magnetron sputtering was used to prepare ZrW₂O₈ films in this paper. The target was the ceramic target made with ZrO₂ and WO₃ powder. Adjusting the experiment parameters such as sputtering atmospheric pressure, sputtering atmosphere, annealing temperature and atmosphere etc. to obtain ZrW₂O₈ film of high purity. The inferences of different sputtering parameters on phase, composition and surface morphology of films had been studied in the paper. X-ray diffraction （XRD）, scanning electron microscope （SEM）, surface profilometer and scratching adhension were used to test the phase, morphology, thickness, cohension of films.The results indicated that, as far as number 1 target （ ZrO₂: WO₃=2: 1 ） was concered, the thinkness of the films decreased with the decrease of the concentration of argon when other para. The thinkness of films was approximately linear with the sputteing time and the sputtering rate was approximately linear with the sputtering power. The cohension of film and the substrate decreased then increased with the increase of the thinkness of the film under a certain range.XRD was used to analyse the phase of films. It is found that the as-deposited film is amorphous. The films prepared with number 1 target crystallized best at around 720℃ based on the results of high and low temperature XRD. When annealed in the RTP-300 rapid treatment furnace, the best treatment temperature is 780℃. While the best temperature is 740℃ when the films made with number 2 target （ZrO₂: WO₃=1: 2. 8 ） annealed in the RTP-300 rapid treatment furnace. When annealed at lower temperature, ZrW₂O₈ film can not crystallize totally. When annealed at higher temperature,ZrW₂O₈ film decompose. SEM photoes reveals that the surface of film is uniform when the treatment temperature is lower than 700℃. When annealed at around 750℃, film are densely packed. When annealed higher temperature than 1000℃, crack更多还原