Contrast in transmission X-ray diffraction topographs of growth defects in the core of SrLaGaO₄ single crystals

Defects in the core of SrLaGaO₄ single crystals, grown by the Czochralski method using a [001]-oriented seed, were studied by transmission X-ray diffraction projection topography. Topographs were taken with radiation from a laboratory source and with high-energy radiation available at the ESRF beamline ID19 in Grenoble. The contrast of the investigated defect images was analysed for various diffraction vectors g and for various values of the product μ₀t (μ₀ is the linear absorption coefficient and t the crystal thickness). This allowed the contrast formation to be studied as a function of absorption. The results of the analysis confirm the model of crystal lattice deformation around rod-like volume defects in SrLaGaO₄ crystals.