PULSED-LASER DEPOSITION OF MOS(X) FILMS IN A BUFFER GAS ATMOSPHERE

The influence of a buffer (inert) gas atmosphere on structure, composition and tribological properties of MoS(x) films formed by pulsed laser deposition with various laser fluences was investigated. The films were deposited at room temperature from an MoS1.8 target under vacuum conditions (4 x 10(-4) Pa) and in Ar atmosphere at a gas pressure varying from 0.7 Pa to 4 Pa. Ablation under vacuum conditions using a relatively low laser fluence resulted in the deposition of amorphous films with conservation of stoichiometry. According to XPS analysis data, such films may contain many defects of chemical nature. Deposition at higher laser fluences resulted in substantial sulphur depletion and, under certain conditions. crystallization of the films. These microcrystalline films exhibited a lower friction coefficient than amorphous ones. Ablation at high laser fluences in Ar atmosphere allowed us to deposit MoS, films with various stoichiometries (x less-than-or-equal-to 2.2) and tribological properties superior to those of the films deposited under vacuum conditions. These films have the amorphous structure and chemistry (according to XPS measurements) inherent in perfect MoS2.