FCC TITANIUM IN TITANIUM SILVER MULTILAYERS

The equilibrium phases of titanium are hcp under 1155 K and bcc above this temperature. However, titanium has been shown to exist as fee whe n its dimensions are small. We have studied the hcp to fee transformat ion in thin titanium layers in an effort to characterize the fee titan ium and to understand the driving force behind the transformation. Mul tilayers of titanium and silver were deposited by electron beam evapor ation, and examined by X-ray diffraction and by transmission electron microscopy. The lattice parameter of the fee titanium was measured to be 0.434 nm and the results eliminated lattice mismatch as a driving f orce, since it has increased by the transformation. (C) 1997 Elsevier Science B.V.