Negative thermal expansion ZrW2O8 thin films prepared by pulsed laser deposition

Negative thermal expansion ZrW2O8 thin films has been grown on quartz substrates by pulsed laser deposition (PLD) method followed by annealing at various temperatures. The influences of annealing temperature on the morphology and phase composition of the ZrW2O8 thin films were investigated. The X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) analyses revealed that the as-deposited ZrW2O8 thin film showed an amorphous phase, the stoichiometry of the as-deposited thin film was close to that of the ZrW2O8 ceramic target, the crystallized cubic ZrW2O8 thin films were prepared after annealing at 1200 °C. The scanning electron microscope (SEM) confirmed that the ZrW2O8 thin film deposited on the substrate heated at 650 °C was smooth and compact, the crystallized cubic ZrW2O8 thin film was a polycrystalline film and its grain size grew 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 the increasing temperatures, which demonstrated that the cubic ZrW2O8 thin film exhibited negative thermal expansion and its thermal expansion coefficient was calculated to be − 11.378 × 10−6 K−1 from 20 °C to 600 °C.

Research highlights
► The negative thermal expansion ZrW2O8 films were successfully prepared using PLD.
► The as-deposited ZrW2O8 thin film shows an amorphous phase.
► The crystallized cubic ZrW2O8 thin films were obtained after annealing at 1200 °C.
► The obtained ZrW2O8 films exhibited excellent negative thermal expansion.
► The thermal expansion coefficient of the ZrW2O8 thin film is − 11.378 × 10−6 K−1.