The effects of deuteration on the nanostructured zirconium films deposited by pulsed laser deposition for nuclear fusion applications

In this paper, zirconium films have been deposited on Al2O3 (0 0 0 1) substrates by pulsed laser deposition (PLD) and then transferred to deuterium atmospheres. We find that the formation of Zr0.38D0.62 is under the deuterated temperatures of 923 K. The surface morphologies, electrical features and optical properties of as-grown zirconium films and zirconium deuteride films are systematically investigated as a function of three pulse repetition rates. It is found that the zirconium films show very smooth surfaces and high specular reflectivity. Moreover, exposure of the as-deposited zirconium films to deuterium atmospheres revealed that some pits formed on the surface of films. These defects induced by deuterium make the specular reflectivity and resistance of films change. The results of our investigation will be useful to optimize the environmental conditions for the First Mirror application in fusion devices.