Fig. 3: Mechanical properties of a suspended CGT/WSe2 (16.7 ± 0.3 nm/6.9 ± 0.1 nm) heterostructure membrane with a radius r = 2 μm.
a Top panel: Schematic cross-section of the sample consisting of the suspended CGT/WSe2 heterostructure membrane and the reference WSe2 membrane of the same flake. Bottom panel: Optical image of the sample with specific membranes indicated. Scale bar: 16 μm. b Measured resonance frequencies f0 of the membranes in (a). Solid green line—the fitted model of the resonance frequency of the CGT/WSe2 heterostructure (Eq. (4)). Light green region—the allowed higher and lower boundary of the model due to the uncertainties in h1,2, E1,2 and \({f}_{0}^{2}({T}_{0})\). Insets: Schematic of a CGT/WSe2 structure with the collinear and random magnetic spin arrangement in a bilayer of CGT in the ferromagnetic (FM) and the paramagnetic (PM) phases respectively. c Dissipation factor Q−1 as a function temperature. The origin of a broad feature at ~20 K remains unclear and is a subject of future studies. d Filled blue circles—\(\, \frac{{{{\rm{d}}}}\left({f}_{0}^{2}\right)}{{{{\rm{d}}}}T}\) of the CGT/WSe2 heterostructure as a function of temperature. Connected magenta circles—the thermal expansion coefficient of bulk CGT5. The black vertical dashed lines in (b–d) indicate the measured \({T}_{{{{\rm{C}}}}}^{* }=58\pm 0.5\) K as determined from the peak position of \(\frac{{{{\rm{d}}}}\left({f}_{0}^{2}\right)}{{{{\rm{d}}}}T}\).
