Synthesis and characterization of oxide interstitial derivatives of zirconium monochloride and monobromide

The reactions of ZrO/sub 2/ (zirconium oxide) with double-metal-layered ZrCl (zironium chloride) and ZrBr (zirconium bromide) at approx. 980/sup 0/C and with Zr metal at 930/sup 0/C have been studied with the aid of high-resolution (Guinier) powder pattern data. The products of the first reaction are ZrX(O/sub y/) (XO/sub y/oxychloride or oxyobromide), an expanded ZrX structure, and Zr(O/sub x/) from solution of ZrO/sub 2/ in the metal, viz., ZrX + nZrO/sub 2/ = ZrX(O/sub y/) + nZr(O/sub x/). The oxygen composition of both products (y,x).varies continuously up to the point of ZrO/sub 2/ saturation where n, y, and x are respectively 0.27 (1), 0.43 (2), and 0.42 for chloride and 0.22 (2), approx. 0.35, and approx. 0.42 for bromide. Single-crystal x-ray results for ZrBrO/sub approx. 0.23/, ZrClO/sub 0.29/, and ZrClO/sub 0/ /sub 43/ establish the retention of the basic ZrX structure (R anti 3 m) and the concentration of oxygen, which is distributed randomly in the distorted tetrahedral interstices between the zirconium layers. The last named composition (a = 3.4984 (2) A, c = 27.065 (4) A) is in equilibrium with ZrO/sub 2/ and gave a refined structure with R = 0.046 and R/sub w/ = 0.056 for 141 independentmore » reflections with 2theta less than or equal to 59.9/sup 0/. UPS (Photoelectron spectroscopy) measurements show that the chloride oxide is still metallic.« less