Synthesis, Structure, and Physicochemical Investigations of the New α Cu_0.50TiO(PO₄) Oxyphosphate.

Abstract

Copper I 7400 Synthesis, Structure, and Physicochemical Investigations of the New α Cu 0.50 TiO(PO 4 ) Oxyphosphate. -The title compound is synthesized by coprecipitation from an aqueous solution of Cu(NO3)2 and NH4H2PO4 by addition of a solution of TiCl4 in EtOH followed by evaporation and heating of the amorphous product in O2 (950°C, 18 h; yield given in g). The crystal structure of the compound is determined by single crystal XRD. α-Cu0.50TiO(PO4) crystallizes in the monoclinic space group P2 1 /c with Z = 4. The structure consists of a TiOPO 4 framework constituted by chains of tilted corner-sharing [TiO6] octahedra and cross linked by [PO4] tetrahedra. One half of the octahedral cavities is occupied by Cu atoms. The compound is further characterized by EPR, optical measurements, IR and Raman spectroscopy, and magnetic measurements. -(BENMOKHTAR, S.; BELMAL, H.; EL JAZOULI*, A.; CHAMINADE, J. P.; GRAVEREAU, P.; PECHEV, S.; GRENIER, J. C.; VILLENEUVE, G.; DE WAAL, D.; J. Solid State Chem. 180 (2007) 2, 772-779; Lab. Chim. Mater. Solides, Fac. Sci. Ben M'Sik, Casablanca, Morocco; Eng.) -W. Pewestorf 51-027

Jahn—Teller Phase Transition in Cu0.50TiO(PO4): Powder Structural Characterization of the β‐Variety and Thermal Study.

“…Study of Cu 0.50 TiO(PO 4 ) compound shows a phase transition with temperature, reversible but with hysteresis. The α-room temperature phase has been characterized : single crystal structure determination with a Jahn Teller deformation of Cuenvironment, and optical study [3]. The present paper reports with structural powder study (X-ray and neutrons) of the β-high temperature phase and with the α→β transition.…”

“…From these powders some tries have been done to obtain single crystals. Some annealings under O 2 flow near decomposition temperature (1000°C) , followed by slow cooling, lead to the formation of α-single crystals (<100μm) which were used for structure determination [3]. But we never succeeded for suitable β-single crystals.…”