Study On ZrW₂O₈ Films Prepared By Radio Frequency Magnetron Sputtering

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...