Potassium Polyuranates

Abstract

A reinvestigation of the system K₂O–UO₃ by diffraction methods and i.r. spectroscopy shows that there are two well defined polyuranate phases. Both are based structurally on layers of uranium in hexagonal array, as found in U₃O₈ and K₂U₂O₇. One polyuranate, isolated in crystalline form is of the diuranate type, with anionic layers 7.045 Å apart, the spacing determined by cation size and packing dimensions of the uranyl group. It has a composition near K₂O ∙ 3 UO₃, but probably a more complex formula. The second, not isolated pure, has K₂O : UO₃ < 1:8, with the layers continuously linked through shared uranyl oxygen atoms, as in α-UO₃. The structural principles of these pseudo-hexagonal layer structures are discussed.