Finite-resolution correction to the diffraction intensity in icosahedral quasicrystals

The correction to the intensity of Bragg scattering by an ideal quasicrystal due to finite experimental resolution is calculated. Intrinsic background intensity is shown to appear due to close filling of the ‘parallel’ reciprocal space by the diffraction spots. This intensity is found as a function of the ‘perpendicular’ wavevector of the strongest peak falling into a particular resolution window and is estimated in a continuous approximation for the one- and three-dimensional quasicrystals. Recent data on the diffraction from a single-grain perfect Al–Pd–Mn quasicrystal are analyzed in a proposed model.