First ultrahigh frequency (UHF) investigation of quality factor Q for the piezoelectric layered structure
«Al/(001)AlN/Mo/(100) diamond» has been executed in a broad frequency band from 1 up to 20 GHz.
The record-breaking Q f quality parameter up to 2.7 1014 Hz has been obtained close to 20 GHz.
Frequency dependence of the form factor m correlated with quality factor has been analyzed by means
of computer simulation, and non-monotonic frequency dependence can be explained by proper features
of thin-film piezoelectric transducer (TFPT). Excluding the minimal Q magnitudes measured at the frequency
points associated with minimal TFPT effectiveness, one can prove a rule of Qf f observed for diamond
on the frequencies above 1 GHz and defined by Landau-Rumer’s acoustic attenuation mechanism.
Synthetic IIa-type diamond single crystal as a substrate material for High-overtone Bulk Acoustic
Resonator (HBAR) possesses some excellent acoustic properties in a wide microwave band and can be
successfully applied for design of acoustoelectronic devices, especially the ones operating at a far UHF
band.