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TiTe2 is trigonal omega structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one TiTe2 sheet oriented in the (0, 0, 1) direction. Ti4+ is bonded to six equivalent Te2- atoms to form edge-sharing TiTe6 octahedra. All Ti–Te bond lengths are 2.78 Å. Te2- is bonded in a 3-coordinate geometry to three equivalent Ti4+ atoms.
Li(TiTe2)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Li1+ is bonded to six Te2- atoms to form LiTe6 octahedra that share corners with twelve equivalent TiTe6 octahedra, edges with two equivalent LiTe6 octahedra, and faces with two equivalent TiTe6 octahedra. The corner-sharing octahedra tilt angles range from 46–49°. There are two shorter (2.88 Å) and four longer (2.91 Å) Li–Te bond lengths. Ti+3.50+ is bonded to six Te2- atoms to form TiTe6 octahedra that share corners with six equivalent LiTe6 octahedra, edges with six equivalent TiTe6 octahedra, and a faceface with one LiTe6 octahedra. The corner-sharing octahedra tilt angles range from 46–49°. There are a spread of Ti–Te bond distances ranging from 2.78–2.82 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three equivalent Ti+3.50+ atoms. In the second Te2- site, Te2- is bonded to two equivalent Li1+ and three equivalent Ti+3.50+ atoms to form a mixture of distorted edge and corner-sharing TeLi2Ti3 trigonal bipyramids.
Li(TiTe2)5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Li1+ is bonded to six Te2- atoms to form LiTe6 octahedra that share corners with twelve TiTe6 octahedra and faces with two equivalent TiTe6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Li–Te bond distances ranging from 2.82–2.84 Å. There are three inequivalent Ti+3.80+ sites. In the first Ti+3.80+ site, Ti+3.80+ is bonded to six Te2- atoms to form TiTe6 octahedra that share corners with three equivalent LiTe6 octahedra and edges with six TiTe6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Ti–Te bond distances ranging from 2.77–2.80 Å. In the second Ti+3.80+ site, Ti+3.80+ is bonded to six Te2- atoms to form TiTe6 octahedra that share corners with four equivalent LiTe6 octahedra and edges with six TiTe6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are four shorter (2.78 Å) and two longer (2.80 Å) Ti–Te bond lengths. In the third Ti+3.80+ site, Ti+3.80+ is bonded to six Te2- atoms to form TiTe6 octahedra that share a cornercorner with one LiTe6 octahedra, edges with six TiTe6 octahedra, and a faceface with one LiTe6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Ti–Te bond distances ranging from 2.78–2.83 Å. There are five inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Ti+3.80+ atoms. In the second Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ti+3.80+ atoms. In the third Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Ti+3.80+ atoms. In the fourth Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Ti+3.80+ atoms. In the fifth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ti+3.80+ atoms.
Single crystals of Zn(.04)Cd(.96)Te was grown by horizontal physical vapor transport (PVT) method and doped by annealing with TiTe2 powder at 600 C for six days. Photorefractive two-beam coupling, along with photoluminescence and absorption spectroscopy, were used to characterize the ZnCdTe:Ti crystal. At 1.32 micrometers, the photorefractive gain has been measured as a function of the grating period. A gain of about 0.16/cm was obtained at an intensity of about 0.1 W/sq cm. The results of this titanium doped ZnCdTe crystal are compared to that of vanadium-doped CdTe crystals reported previously.