Фазовая диаграмма системы Li-Pd

К оглавлению: Другие диаграммы (Others phase diargams)

Li-Pd (Lithium-Palladium) J. Sangster and A.D. Pelton Liquidus and solidus points of the assessed Li-Pd phase diagram, as well as temperatures of invariant reactions, were obtained by DTA [77Loe]. No other study of the equilibrium diagram has been reported. The samples for the DTA measurements [77Loe] were prepared by direct reaction of Li of 99 at.% purity with Pd of 99.9 at.% purity. The measurements were made in sealed tantalum containers under argon at heating and cooling rates of 5 to 10 C/min [77Loe, 81Loe]. The authors state that measurements of the liquidus above about 700 C were essentially impossible due to reaction of Li with the tantalum container. They even observed this exothermic reaction in their DTA experiments. Furthermore, at higher temperatures, Li escaped from the sealed containers and reacted with the Al2O3 supports. Due to the experimental difficulties, the sparseness of the results, and the lack of confirmation by other authors, the assessed diagram above 700 C and above 50 at.% Pd is very tentative. Even at lower temperatures, error limits of с25 to 50 C should be placed on all DTA points, and the identification of the invariant reactions should be considered to be tentative. There is, however, confirmatory evidence for the existence of most of the compounds [ 66Fer, 68Fer, 76Vuc, 77Loe, 77Nac]. The solubility of Li in solid (Pd) has been reported from X-ray data [77Loe] to be ~6 at.% at 600 C. According to [76Vuc], the temperature of maximum solubility is 800 C. 66Fer: R. Ferro, Atti Accad. Naz. Lincei, Rend. Cl. Sci. Fis. Mat. Natur., 41( 5), 348-350 (1966). 68Fer: R. Ferro, R. Capelli, S. Delfino, and G. Centineo, Atti Accad. Naz. Lincei, Sci. Fis. Mat. Natur. Rend., 45(6), 564-566 (1968) in Italian. 76Vuc: J.H.N. Van Vucht and K.H.J. Buschow, J. Less-Common Met., 48(2), 345- 347 (1976). 77Loe: O. Loebich and C.J. Raub, J. Less-Common Met., 55(1), 67-76 (1977) in German. 77Nac: B. Nacken and W. Bronger, J. Less-Common Met., 52(2), 323-325 (1977) in German. 81Loe: O. Loebich and C.J. Raub, Platinum Met. Rev., 25(3), 113-120 (1981). Submitted to the APD Program. Complete evaluation contains 1 figure, 2 tables, and 7 references. 1