The low-temperature hexagonal phase Na4Ti5O12

The X-ray diffraction study has shown that the compound that was earlier de scribed as Na2Ti2O5 really corresponds to the formula Na4Ti5O12 and has the structure based on the dense stacking anion with the parameters of the hex agonal unit cell a = 5.319 Angstrom, c = 9.556 Angstrom, Z = 1. This compou nd differs from another polymorph of the same composition by the absence of ion-exchange properties. The more efficient method of synthesis is develop ed. Due to its instability above 700 degrees C, the compound is a convenien t intermediate in the syntheses of ternary sodium titanates.