Effect of gas pressure on the quality-factor of single-crystal diamond micro cantilevers

Abstract

Single-crystal diamond (SCD) is a prominent semiconductor material due to its superior mechanical and physical properties. From the viewpoint of practical application, a low vacuum or atmospheric environment are preferred. Here we systematically investigated the effect of ambient gas pressure on the quality-factor (Q-factor) of SCD micro cantilevers, and analyzed the disparate energy dissipation mechanisms. The Q-factor around 7500 was found to be almost stable for ambient pressure <10 Pa, then decreased sharply by about three orders of magnitude with the pressure increasing up to 105 Pa gradually. The ambient pressure ranging from 10−3 to 105 Pa can be defined as intrinsic, molecular, and viscous regimes by Knudsen number. We found that the Q-factors of the SCD cantilevers can be well described by the analytical models corresponding to the three regimes.