Figure 3.

(a) Measured Q_m values for different temperatures, cantilever lengths and materials: single crystal diamond (SCD) in electronic-grade (EG) and optical-grade (OG), polycrystalline diamond (PCD) and single-crystal Silicon (Si). Arrows indicate record Q_m reported in the text. (b) Inferred and projected sensitivities for force measurement of different cantilevers versus temperature and thickness for B=1 Hz. Data from Refs. 24,27,37,39,40,43. The arrows indicate current best realization with diamond and silicon, while the circles indicate the required sensitivity for nuclear magnetic resonance signals using spin magnetic resonance force microscopy. Experiments in the range 3 K to 300 K show²⁷ that EG SCD gives Q_m factors up to one order of magnitude higher than optical-grade single crystal diamond, comparing cantilevers of similar thickness (100–300 nm).