Isomorphic substitution of samarium for strontium in the Sr-5(VO4)(3)OH structure

Using the X-ray phase analysis and IR spectroscopy, the isomorphic substitution of samarium for strontium according to the Sr2++OH--> Sm3++O2- has been studied in a synthetic hydroxyapatite corresponding to the system composition Sr5-xSmx(VO4)(3)(OH)(1-x)O-x (0 <= x <=.40). The solid solutions on the basis of strontium hydroxyapatites (synthesized at 800 degrees C from solutions) have been established to be formed within limits 0<x<0.12. The crystal structure of the solid solutions obtained has been refined by the Rietveld method.