Studies of the impurity effects on crystalline quality by high-resolution X-ray diffraction

Sr(NO3)(2) single crystals with different impurities doped were grown from aqueous solutions. The distribution of impurities in Sr(NO3)(2) crystals we re investigated by electron probe micoranalysis. Results show that the dist ribution of impurities illustrates a compositional zoning behaviour. The Ba 2+ has a higher concentration in the {100} growth sectors than in the {111} sectors. On the contrary, Pb2+ has a higher concentration in {111} growth sectors than in {100} sectors. The crystalline perfection of the pure and B a2+ or Pb2+ doped Sr(NO3)(2) crystals was studied by high-resolution X-ray rocking curve technique. The high-resolution X-ray rocking curve of the ide al Sr(NO3)(2) Crystal was theoretically calculated based on the dynamical X -ray diffraction theory. High-resolution X-ray diffraction results show tha t the crystalline quality in the growth sectors of the pure Sr(NO3)(2) crys tal is fairly high, since its experimental rocking curve is very close to t he theoretical calculation. However, in the areas of the sector boundary th e full width at half maximum of the rocking curve gets broader due to the l attice stress in the boundary area. The doping of impurities will deteriora te the quality of the crystal and induce an inhomogeneity behaviour of the crystalline quality. As for the Ba2+ doped Sr(NO3)(2) crystal, the crystall ine quality in {111} growth sectors is higher than that in {100} sectors. O n the contrary, the crystalline quality in {100} growth sectors is higher t han that in {111} sectors for Pb2+ doped Sr(NO3)(2) crystal. This coincides well with the composition distributions of the dopants.