ATOMIC OXYGEN MOS2 CHEMICAL INTERACTIONS

The present study shows that an an O-atom translation energy of 1.5 eV, SO2 is generated and outgases from an anhydrous MoS2 surface with an initial reactivity nearly 50% that of kapton. The reaction of atomic oxygen with MoS2 has little or no translational energy barrier, i.e. thermally generated atomic oxygen reacts as readily as that having 1.5 eV of translational energy. For MoS2 films sputter-deposited at 50-70 °C, friction measurements showed a high initial friction coefficient (up to 0.25) for MoS2 surfaces exposed to atomic oxygen, which dropped to the normal low values after several cycles of operation in air and ultrahigh vacuum. For MoS2 films deposited at 200 °C, the friction coefficient was not affected by the O-atom exposure. © 1989.