Abstract:The ZrW2O8 thin film of negative thermal expansion (NTE), as a novel functional material, has various potential applications in optics, microelectronics and micro-machine. The ZrW2O8 thin films were deposited on different substrates by RF magnetron sputtering with pure ZrW2O8 ceramic as target. The performance of target and the effects of post-deposition annealing temperature, atmosphere and substrate on the microstructure and morphology of the ZrW2O8 thin films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that the target is compact and composed of pure ZrW2O8. The as-deposited ZrW2O8 film shows an amorphous phase. The ZrW2O8 film with preferred orientation can be prepared in oxygen atmosphere by annealing at 730 ℃, the trigonal ZrW2O8 film can be prepared by annealing at 750 ℃, and the cubic ZrW2O8 film can be prepared in a sealed cell at 1200 ℃, and the negative thermal expansion coefficient of the resulting cubic ZrW2O8 film is –14.47×10-6 K-1 in the temperature range from 15 ℃ to 700 ℃. With the increase of annealing temperature, some holes and deficiencies appear in the surface of films