Spin crossover materials for MEMS actuation: Film integration and characterization

This work describes the integration of molecular spin crossover (SCO) compound [Fe(H
₂
B(pz)
₂
)
₂
(phen)] 1 (H
₂
B(pz)
₂
= dihydrobis(pyrazolyl)borate, phen = 1,10phenantroline) into silicon MEMS with the aim to determine the mechanical properties of the SCO thin film. Analytical methods using the experimental resonance frequency before and after deposition of 1 are used to extract the elastic modulus (E) and residual stress (σ) induced by the film deposition, leading to values of E = 6.9 ± 0.1 GPa and σ = 74.8 MPa respectively. Additional mechanical parameters as a consequence of the expected spin transition were also predicted. These results provide a step towards the integration of SCO materials for future applications as actuators in MEMS/NEMS devices.