A study of the non-stoicheiometric, lime-type phase occurring in the system Ca-O-N

Abstract

A brown, strongly reducing, non-stoicheiometric calcium oxynitride phase has been prepared by heating calcium oxide pellets at about 1100º in an atmosphere of calcium vapour and nitrogen derived from heated calcium nitride. The compositions studied ranged between CaN_o.oo4O_0.99(2) and CaN_o.070O_0.82(5). X-ray diffraction patterns were of a face-centred cubic lime-type phase with lattice parameters expanded with respect to that of pure lime; the expansion was a linear function of the nitrogen content. The possible nature of this non-stoicheiometric solid is discussed.