Materials Research Bulletin, Vol.36, No.13-14, 2531-2541, 2001
Synthesis of the fibrous materials rho-Na0.50H0.50TiOPO4 and rho-K0.67H0.33TiOPO4 by reaction of rho-Ti2O(PO4)(2)(H2O)(2) with molten alkali nitrates
The reaction of rho -TiP with molten MNO3 (M = Na, K) originates the formation of new metal phases, rho -MxH1-xTiOPO4 (x = 0.50, M = Na; x = 0.67, M = K). These compounds maintain the fibrous morphology of their precursors. The processes occur in two differentiated steps with formation of rho -MxH1-xTiOPO4 (x = 0.25, M = Na; x = 0.42, M = K) intermediate phases. An ion-exchange mechanism is proposed for the reaction. Thermal treatment of the novel fibrous alkali metal phosphates produces mixtures of MTiOPO4, MTi2(PO4)(3), and TiO2.