Фазовая диаграмма системы La-Mg

К оглавлению: Другие диаграммы (Others phase diargams)


La-Mg (Lanthanum-Magnesium) A.A. Nayeb-Hashemi and J.B. Clark The assessed Mg-La phase diagram in the composition range 40 to 100 at.% La is based on the results of [86Man], with some modification. The findings of [ 86Man] are considered the most reliable data in this composition range. The rest of the system is based on the results of [31Can], [40Wei], [47Vog], [ 57Par], [65Jos], and [79Dar]. It consists of: (1) the liquid, L; (2) the terminal (Mg) solid solution; (3) the terminal (aLa), (bLa), and (gLa) solid solutions; and (4) five intermetallic compounds (Mg12La, with some homogeneity range; Mg17La2; Mg3La, with some homogeneity range; Mg2La; and MgLa, with a homogeneity range). In the assessed diagram, the (Mg) liquidus curve is taken from [40Wei], and the portion of the liquidus between 2.3 and 20 at.% La is taken from [31Can] and [47Vog]. In the composition range 2.5 to ~8.5 at.% La, the liquidus curve is shown as a dashed line, because there are no reliable data. The Mg-rich eutectic point is placed at 2.3 с 0.1 at.% La and 613 с 3 C. [57Par] placed the maximum solid solubility of La, Ce, Pr, and Nd in (Mg) at 0. 14 at.% La, 0.09 at.% Ce, 0.09 at.% Pr, and 0.1 at.% Nd. These data are preferred for the present evaluation, but an independent investigation is needed to determine unequivocally the variation of the solid solubility of the light lanthanides (La to Nd) in (Mg), due to wide scatter of experimental data. In the assessed diagram, the evaluators show the (bLa) solvus curve as a dashed line to indicate its uncertainty. In the range 4 to 300 K, [73Bus] and [76Bus] investigated the magnetic properties of MgRE and Mg3RE compounds, respectively. MgLa and Mg3La were found to be Pauli paramagnetic. [78Bus] studied the magnetic properties of Mg2RE compounds in the temperature range 1.5 to 300 K and the magnetic field of up to 18 kOe. According to [78Bus], most of the Mg2RE compounds order ferromagnetically at temperatures "well below 100 K," except for Mg2La, Mg2Yb, and Mg2Y, which show Pauli paramagnetism. Mg2Sm and Mg2Eu order antiferromagnetically. 31Can: G. Canneri, Metall. Ital., 23, 803-823 (1931) in Italian. 34Ros1: A. Rossi and A. Iandelli, Accad. Naz. Lincei, 19, 415-420 (1934) in Italian. 34Ros2: A. Rossi, Gass. Chim. Ital., 64, 774-778 (1934) in Italian. 40Wei: F. Weibke and W. Schmidt, Z. Electrochem., 46, 359-362 (1940) in German. 42Now: H.J. Nowotny, Z. Metallkd., 34, 247-253 (1942) in German. 43Lav: F. Laves, Naturwissenschaften, 31, 96 (1943) in German. 43Rol: L. Rolla, A. Iandelli, G. Canneri, and R. Vogel, Z. Metallkd., 35, 29- 42 (1943) in German. 47Vog: R. Vogel and T. Heumann, Z. Metallkd., 38, 1-8 (1947) in German. 57Par: J.J. Park and L.L. Wyman, WACD Tech. Rep. 57-504, 33 p (1957). 59Ian: A. Iandelli, Natl. Phys. Lab., Great Britain, Proc. Symp. No. 9, Vol. I, Paper 3F, 11 p (1959). 63Evd: V.I. Evdokimenko and P.I. Kripyakevich, Kristallografiya, 8, 186-193 ( 1963) in Russian; TR: Sov. Phys. Crystallogr., 8, 135-141 (1963). 65Jos: R.R. Joseph and K.A. Gschneidner, Jr., Trans. AIME, 233, 2063-2069 ( 1965). 66Cha: C.C. Chao and P. Duwez, J. Appl. Phys., 37(7), 2631-2632 (1966). 73Bus: K.H.J. Buschow, J. Less-Common Met., 33, 239-244 (1973). 76Bus: K.H.J. Buschow, J. Less-Common Met., 44, 301-306 (1976). 78Bus: K.H.J. Buschow, R.C. Sherwood, and F.S.L. Hsu, J. Appl. Phys., 49(3), 1510-1512 (1978). 79Dar: B. Darriet, M. Pezat, A. Hbika, and P. Hagenmuller, Mater. Res. Bull., 14, 377-385 (1979) in French. 81Pie: J. Pierre, A.P. Murani, and R.M. Galera, J. Phys. F, Met. Phys., 11, 697-698 (1981). 86Man: P. Manfrinetti and K.A. Gschneidner, Jr., J. Less-Common Met., 123, 267- 275 (1986). Published in Phase Diagrams of Binary Magnesium Alloys, 1988, and Bull. Alloy Phase Diagrams, 9(2), Apr 1988. Complete evaluation contains 1 figure, 6 tables, and 36 references. Special Points of the Mg-La System