Фазовая диаграмма системы La-Tl

К оглавлению: Другие диаграммы (Others phase diargams)


La-Tl (Lanthanum-Thallium) S. Delfino, A. Saccone, A. Palenzona, and R. Ferro The assessed phase diagram for the La-Tl system is based on [85Del] and on [ 76Mcm] for the range of 0 to 25 at.% Tl. The melting points of the pure metals and the transformation temperatures have been adjusted slightly to conform to [ Gschneidner]. The eutectoid reaction (decomposition of (gLa) into (bLa) and La3Tl) occurs at 10.0 at.% Tl and 640 C. Metallography results suggest a homogeneity range of about 1 at.% (6 to 7 at.% for LaTl) for the intermediate phases, except for LaTl3. The structure of La2Tl has not been determined. Indications of this phase were obtained from thermal and metallographic data and electron probe microanalysis. The maximum solid solubility of Tl in (gLa) is 11.0 at.% Tl at the 655 C eutectic temperature; the solubility in (bLa) is 1.9 at.% Tl at the 640 C eutectoid temperature. The solid solubility of La in (bTl) and (aTl) is assumed to be negligible. Thermodynamics and magnetic properties of La-Tl alloys as well as the general properties of RE-Tl alloys have been discussed by [88Sac]. 76Mcm: O.D. McMasters and K.A. Gschneidner, Jr., J. Less-Common Met., 44, 281 ( 1976). 85Del: S. Delfino, A. Saccone, G. Cacciamani, and R. Ferro, Z. Metallkd., 76, 7 (1985). 88Sac: A. Saccone, S. Delfino, and R. Ferro, J. Less-Common Met., 143, 1 (1988) . Submitted to the APD Program. Complete evaluation contains 1 figure, 1 table, and 5 references. 1