Amplification of Surface Acoustic Waves in Graphene Film under DC Voltage

D.V. Roshchupkin, O.V. Kononenko, K. Tynyshtykbayev, Z. Insepov
Purdue University, US

Keywords: calcium–tantalum-gallium silicate, surface acoustic waves, X-Ray diffraction

Summary:

An acoustoelectric effect has been experimentally studied in a graphene film fabricated on the top of a piezoelectric crystal of the lanthanum–gallium silicate family Ca3TaGa3Si2O14 (CTGS) grown by the Czochralski method. The unit-cell parameters were determined by the powder diffraction technique as follows: the CTGS crystal has a 32 space group symmetry, and the unit cell is hexagonal with a = b = 2d(110) = 8.14860 Å and c = d(001) = 4.98822 Å. Significant amplification of the surface acoustic waves (SAW) has been observed experimentally in the Y-cut of the CTGS crystal coated with a graphene film synthesized by CVD, using a high-resolution X-Ray diffractometer Bruker D8 DISCOVER. Observation of the diffraction satellites on the rocking curves obtains the number, angular positions, and the intensities of the diffraction patterns depending on the wavelength and amplitude of acoustic vibrations of the graphene crystal lattice, the electric potential of which was biased at a DC potential. The X-Ray diffraction spectra obtained at a DC electric potential ±10V applied to the graphene film showed a significant (almost 100%) amplification of SAW magnitudes.