Characterization of dislocations and sub-grain boundaries in mixed rare earth orthovanadate of Yb : Y_xLu_1-xVO₄

Mixed crystal of Yb:Y_xLu_1−xVO₄ was grown by Czochralski method. Defects of dislocations and sub-grain boundaries in Yb:Y_0.71Lu_0.29VO₄ single crystal were studied by using chemical etching and synchrotron X-ray topographic methods. Some of the three intersecting boundaries were revealed by chemical etching method in Yb:Y_0.71Lu_0.29VO₄ crystal. The generalized Read–Shockley formula for intersecting boundaries was introduced to verify the one-to-one correspondence between etching pits along these sub-boundaries and edge dislocations with Burgers vectors of 〈1 0 0〉. Synchrotron X-ray topographic confirmed that the dominating imperfections in the studied Yb:Y_0.71Lu_0.29VO₄ single crystal are a variously developed block structure and sub-grain boundaries.