Measurement of the mechanical loss of crystalline samples using a nodal support

A megahertz nanomechanical resonator with room temperature quality factor over a million

“…22 This mode has a Q value of 6.8ϫ 10 5 , for an fQ product of 6.8ϫ 10 12 Hz, of the same order as previously demonstrated with much larger lower frequency singlecrystal bulk resonators 15 and within a factor of ϳ2 -3 of that attained with higher frequency micromechanical systems. The 10.02 MHz mode of a 325-m-long device was measured shortly after a hot-plate bake step which has previously been observed to lead to moderate improvements in quality factor for similar devices.…”

“…[12][13][14] Whereas macroscopic audiofrequency oscillators have been reported with Q as high as 10 8 at room temperature, 15 devices with cross sections on the order of 100 nm tend to exhibit Q well below 10 5 . For this application there is an advantage to achieving maximum quality factor as well as frequency, while minimizing device size.…”

Mechanical dissipation in silicon flexures

“…The level of intrinsic and expected thermo-elastic dissipation in silicon is broadly comparable to sapphire at room temperature [8]. However on cooling the linear thermal expansion coefficient of silicon becomes zero at two temperatures, ~125 K and ~18 K [9], and thus around these two temperatures thermoelastic dissipation could be expected to be negligible.…”

Fluctuation Dissipation at work: Thermal noise in reflective optical coatings for GW detectors

“…However, in order to further reduce the thermal noise level cooling is a very promising option. In this case, crystalline materials, as silicon or sapphire, are promising candidates due to their excellent low mechanical losses [15], [16] and high thermal conductivity [17] at cryogenic temperatures. These materials are non-isotropic in nature and thus the strategy to determine thermal noise as described above needs to be reviewed.…”