Thermodynamic investigation of Ti-H system by molten salt electrochemical technique

We have investigated the thermodynamic properties of the Ti-H system includ ing the high-concentration region (TiHchi: 0 < chi < 1.8) by utilizing the electrochemical reaction of the hydride ion, H-, in a molten LiCl-KCl-LiH s ystem. Electrode potential-composi tion isotherms in three single phases, a lpha, beta, and delta, and in two coexisting phases, (alpha + beta) and (be ta + delta), have been measured at 673-773 K. The relative partial molar qu antities of absorbed hydrogen, DeltaG(H), DeltaH(H), and DeltaS(H), and int egral quantities, DeltaG(f)(0)(TiH2), DeltaH(f)(0)(TiH2), and DeltaS(f)(0)( TiH2), were estimated. It was confirmed that the obtained results were in g ood agreement with the reported values derived by using other techniques. ( C) 2000 The Electrochemical Society. S0013-1651(00)01 -039-9. All rights re served.