Dynamical theory for calculations of X-ray spectra from crystals modulated by surface acoustic waves

Abstract

The dynamical theory was used to model X‐ray diffraction by the YZ‐cut of an LiNbO3 crystal modulated by surface acoustic waves (SAWs). It includes both the calculation of the crystal lattice deformation, induced by a surface wave of Rayleigh type, and the simulation of X‐ray wavefields in the crystal based on Takagi–Taupin equations. A detailed discussion is included on the effect of peak splitting occurring at high acoustic amplitudes. The developed theory entirely describes this effect and proves to be a powerful tool for understanding X‐ray diffractometry and topography measurements by SAW‐modulated crystals.

Time-resolved coherent X-ray diffraction imaging of surface acoustic waves

“…A larger P SAW clearly leads to an increase in intensity of the satellite peaks, here shown at constant phase '. This observation is in line with previous (incoherent) reflectivity measurements of SAWs (Tucoulou et al, 2000(Tucoulou et al, , 2001) and theoretical calculations (Schelokov et al, 2004).…”

X-ray imaging of the surface acoustic wave propagation in La<inf>3</inf>Ga<inf>5</inf>SiO<inf>14</inf> crystal

“…Unlike scanning electron microscopy, X-ray diffraction and topography are the methods of quantitative analysis and permit studying acoustic wave fields both in piezoelectric and non-piezoelectric materials. Using high-resolution X-ray diffraction, amplitudes and wavelengths of acoustic wave can be determined, acoustic waves attenuation in the crystal depth and along their propagation direction can be measured by the analysis of their X-ray diffraction spectra [6][7][8][9][10]. Stroboscopic X-ray topography, like SEM, permits direct imaging of an acoustic wave field in the real time mode [6,[11][12][13][14].…”

Effect of the ultrasonic frequency on the multiple X-ray scattering from a LiNbO3 crystal modulated by a surface acoustic wave

“…In these crystals the SAW ampli tude can be varied in a wide range (from zero to several angstroms) by changing the amplitude of the high fre quency electric signal applied to interdigital trans ducer (IDT). X ray diffraction, which is highly sensitive to lattice strain, is successfully used to study acoustic waves in near surface layers of crystals [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The specific features of SAW propagation in solids were monitored by X ray topography [3][4][5], grazing X ray diffraction [6,7], and double and triple crystal X ray diffraction [8][9][10][11][12][13][14][15][16][17].…”