论文部分内容阅读
Negative thermal expansion ZrW2O8 thin films have been grown on quartz substrates by pulsed laser deposition (PLD) method using ZrW2O8 ceramic target and annealing subsequently.The influences of annealing temperature on the growth morphology and phase composition of the ZrW2O8 thin films were investigated.The X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) analyses confirmed that the as-deposited ZrW2O8 thin film shows an amorphous phase,the stoichiometry of the as-deposited film is close to that of the ZrW2O8,the crystallized cubic ZrW2O8 thin films were prepared after annealing at 1 200℃.The field emission scanning electron microscope (FESEM) confirmed that the film deposited on the substrate heated at 650 ℃ is smooth and compact,the crystallized cubic ZrW2Os thin film is polycrystal film and its grain size grows to be larger.The High temperature X-ray diffraction analyses showed that all the peaks ascribe to the ZrW2O8 thin film shifted to higher angle with increasing test temperature,which confirmed the cubic ZrW2O8 thin film exhibited excellent negative thermal expansion property,and an α to β structure phase transition occured between 100 ℃ and 200 ℃.