Examination of crystal defects with high-kV X-ray computed tomography

High resolution X-ray computed tomography (CT) is shown to be a useful technique for characterizing the defect known as scatter in Nd-doped yttrium orthovanadate (Nd:YVO4) single crystals. Scatter is identified by a dense cloud or rings of defects, which cause crystal inhomogeneity. Computed tomography indicated that the scattering sites were regions of low density. This result rules out micropieces of iridium and the segregation phases of V2O5 and Y2O3 as the main scattering centers. Transmission electron microscopy has shown, however, that inclusions are nonetheless present in regions of the crystal containing scatter. The major scattering defect in the crystal was determined to be microvoids which are approximately 10 μm in diameter.