A new synthetic route to pseudo-brookite-type CaTi2O4

A new synthetic route to the reduced calcium titanate CaTi2O4 has been disc overed. Single crystals of CaTi2O4 were grown by the reduction of CaTiO3 wi th Ti metal powder in a CaCl2 flux under Bowing nitrogen at 1000 degrees C. The pseudo-brookite-type structure of CaTi2O4 was redetermined from single crystal X-ray diffraction data and refined to an R value of 0.016. CaTi2O4 crystallizes in the orthorhombic space group Bbmm: a = 9.718(4) Angstrom, b = 9.960(4) Angstrom, and c = 3.140(2) Angstrom with four formula units pe r unit cell. The structure is built up from edge-sharing chains of TiO6 oct ahedra that condense to form one-dimensional tunnels in which the calcium a toms are located. This new synthetic route provides a simple method of obta ining high quality samples of CaTi2O4 for further study. (C) 1998 Academic Press.