Titanium Crystal

Titanium is expecting as a bandpass filter, which transmits the ray in l: 33–60 nm.

Crystal System

Ti takes two types of crystal systems, the a-type (low temperature type) and the b-type (the high temperature type is stable above 882℃). The space lattice of a-Ti belongs to the hexagonal system, and its hexagonal closed-packing lattice has lattice parameters of a=0.292 nm, c=0.467 nm. The space lattice of b-Ti belongs to the cubic system, and its body centered lattice hasalattice parameter of a=0.3327 (900℃).

Production

Ti is contained in rocks and soil, and occupies 0.8% of the crust as TiO2. Source minerals are TiO2, FeTiO3, CaTiO3, etc., Ti is obtained by the thermit process or by reducing TiCl4 with Na or Mg. Thin films are deposited by vacuum evaporation using a conical basket type heater of chromel, Ta or W, or a carbon crucible heated by direct current feeding. Heating by the electron beam is also effective. There is the possibility for W to incorporate within a deposited film because Ti reacts with W. The rate of evaporation is 9.47×10^-4g/cm2 s at the evaporation temperature of 1546℃.