New gadolinium-substituted lead sodium apatite structure

Abstract

The substitution of gadolinium by lead in the compound Pb₈-xNa₂Gdx(PO₄)₆Ox/₂, in accordance with the scheme 2Pb²⁺ + • ↠ 2Gd³⁺ + O2- was studied by means of powder X-ray diffraction (including the Rietveld refinement). It was established that solid solutions apatite samples are synthesized at 900 °C between the range from x = 0.0 up to x = 1.0. Rietveld method shows that Gd³⁺ is located in positions Pb(2), resulting in the distance in a polyhedron Pb(2) where the structure of apatite decreased.