Solid solutions of composition TizlM0.3(Sbl-xNbx)o.606 (M=Co, Ni and Cu) in the range 0 _< x<_ 1 are obtained by thermal treatment of the appropriate amounts of simple oxides. The crystal structures have been determined by employing Rietveld structure analysis of powder X-ray diffraction data. Electrical conductivity, magnetic and ultraviolet photoelectron spectrometry (UPS) measurements for these phases are also discussed.
-1. Introduction
Rutile is an important structure for many binary oxides MOe, in which metal is octahedrally (slightly distorted) coordinated to six oxygen, and each anion is in planar three-coordination with metal cations. This structure is built up chains of MO6 octahedra sharing opposite edges linked to other chains, rotated 90 ~ in the c direction, by sharing corners Previous works concerning titanium, antimony and niobium mixed oxides with the general formula Ti2.1MxM~O6 [1-3] have been reported.. It was shown that these compounds adopt the rutile or trirutile type structure. Often, certain properties of such materials (magnetic, mechanical, electrical, etc.) can be modified by changing the composition, and it seemed interesting to develop previous knowledge of other solid phases with this structure. Some ternary oxides of the transition elements are currently being investigated as potential candidates for electrodes in solidstate batteries.
In this study Ti2.1Mo.3(Sbl-xNb~)o.606 (M = Co, Ni and Cu, 0 _< x _< 1) solid solutions have been prepared. The structural characterizations of these compounds have been obtained from X-ray powder diffraction and the conductivity and susceptibility magnetic measurements determined on polycrystalline materials. The ultraviolet photoelectron spectrometry (UPS) measurements have allowed information to be obtained on the occupied electronic states of the valence band regions up to the Fermi energy, Ef, but they have not provided a determination of the d ~ level's exact position. Moreover, the study carried out by scanning electron microscopy confirms grainboundary effects to be absent.