Фазовая диаграмма системы Ga-Gd

К оглавлению: Другие диаграммы (Others phase diargams)


Ga-Gd (Gallium-Gadolinium) A. Palenzona and S. Cirafici The assessed phase diagram for the Ga-Gd system has been drawn taking into account primarily the work of [77Yat] and [79Yat], with review of the experimental data of [79Bus]. The Ga-rich side is based on [81Pel1]. The nature of the Ga-rich eutectic has not yet been defined. The equilibrium phases of the Ga-Gd system are (1) the liquid, L; (2) the five intermediate phases: Ga6Gd, Ga2Gd, GaGd, Ga2Gd3, and Ga3Gd5; and (3) the two terminal solid solutions, (Ga) and (Gd), with negligible solubility. [76Bus] found four intermediate phases: Ga2Gd, GaGd, Ga2Gd3, and Ga3Gd5. [ 77Yat] and [79Yat] confirmed substantially the results of [76Bus] with a study based on a higher number of alloys. Four intermediate phases were found at the same stoichiometries as those found by [76Bus], but with slight differences in their melting temperatures: Ga2Gd (1400 C), GaGd (1200 C), Ga2Gd3 (1120 C), and Ga3Gd5 (1100 C). The eutectic point was fixed at 80 at.% Ga and 850 C. [ 81Pel1] found the Ga-rich phase, Ga6Gd, formed at 379 C by a peritectic reaction and common to almost all other Ga-RE systems. The solubility of Gd in liquid Ga, between 400 and 800 K, was determined by [ 72Yat] and can be expressed as log C = 1.90 - 1.59 x 103/T where C is in atomic percent Gd and T is in K. Very little is known about metastable phases in the Ga-Gd system. [80Bus] investigated the magnetic properties and ferromagnetic resonance of Ga21Gd79 and Ga25Gd75 alloys. The samples were prepared by arc melting followed by melt spinning in an argon atmosphere. Thermal stability and crystallization temperatures were studied by differential scanning calorimetry at 50 C/min. Magnetic measurements were carried out between 4.2 and 300 K. Both samples are ferromagnetic; transition temperature, Curie temperature, and magnetic moments were determined. [71Bus] found a ferromagnetic behavior for GaGd below 210 K; this was confirmed by [71Fuj], who fixed the transition temperature at 183 K and found a Curie-Weiss behavior in the paramagnetic region from 4.2 to 400 K. [72Bar] also confirmed the transition at 190 K. [76Bus] investigated the magnetic properties of the Ga-Gd phases in the range ~10 to 300 K. Ga3Gd5 and Ga2Gd3 are antiferromagnetic below 80 and 55 K, respectively, and follow a Curie-Weiss law up to room temperature. GaGd is ferromagnetic with a transition temperature of 200 K, and Ga2Gd follows the Curie-Weiss law down to 30 K. [76Hac1] confirmed the magnetic properties for Ga2Gd3 in the range 8 to 300 K, finding an antiferromagnetic transition at 53 K. [76Hac2] examined Ga2Gd by electron paramagnetic resonance and magnetic measurements. The results indicate ferrimagnetic behavior with Tc = 181 K. Above 250 K, the compound follows a Curie-Weiss law; over the range 190 to 300 K, the data obey a N‚el- type law, indicative of a ferrimagnetic order. [78Tsa] studied the magnetic properties of polycrystalline Ga2RE phases from 1. 5 to 300 K. An antiferromagnetic transition was found for Ga2Gd at 12.1 K, followed by a Curie-Weiss behavior up to 300 K. [79Tsa] investigated magnetic ordering and exchange interaction in polycrystalline Ga2RE compounds in the range 1.5 to 300 K. Ga2Gd shows a negative paramagnetic Weiss temperature. [86Tag] investigated the magnetic properties in the range 4.2 to 300 K and electrical resistivities in the range 1.7 to 300 K of Ga6RE phases. Ga6Gd shows an antiferromagnetic transition at 12.6 K, followed by a Curie-Weiss behavior. 61Bae1: N.C. Baenziger and J.L. Moriarty, Acta Crystallogr., 14, 946-947 (1961) . 61Bae2: N.C. Baenziger and J.L. Moriarty, Acta Crystallogr., 14, 948-950 (1961) . 61Has: S.E. Haszko, Trans. Met. Soc. AIME, 221, 201-202 (1961). 65Dwi: A.E. Dwight, Argonne Nat. Lab. Annu. Progr. Rep., Met. Div., U.S. At. Energy Comm. ANL-7155, 234-237 (1965). 67Ram: A. Raman, Z. Metallkd., 58, 179-184 (1967). 68Pal: A. Palenzona and E. Franceschi, J. Less-Common Met., 14, 47-53 (1968). 69Dzy: D.I. Dzyana and P.I. Kripyakevich, Dopl. Akad. Nauk Ukr. RSR, Ser. A, 31, 247-250 (1969) in Russian. 71Bus: K.H.J. Buschow, Phys. Status Solidi (a), 7, 199-210 (1971). 71Fuj: J. Fujii, N. Shohata, T. Okamoto, and E. Tatsumoto, J. Phys Soc. Jpn., 31, 1592 (1971). 72Bar: B. Barbara, Van Nhung Nguyen, and E. Siaud, C.R. Acad. Sci. Paris, 274B, 1053-1056 (1972). 72Yat: S.P. Yatsenko, Yu.A. Anikin, and E.N. Dieva, Izv. Akad. Nauk SSSR, Met., (2), 213-214 (1972) in Russian. 76Bus: K.H.J. Buschow and W.W. Hoogenhof, J. Less-Common Met., 45, 309-313 ( 1976). 76Hac1: H. Hacker, Jr. and R.M. Gupta, J. Less-Common Met., 45, 331-332 (1976). 76Hac2: H. Hacker, Jr., J. Solid State Chem., 17, 319-322 (1976). 77Yat: S.P. Yatsenko, J. Chim. Phys., 74, 836-843 (1977). 78Tsa: T.H. Tsai, J.A. Gerber, J.W. Weymouth, and D.J. Sellmyer, J. Appl. Phys. , 49(3), 1507-1509 (1978). 79Tsa: T. Tsai and D.J. Sessmyer, Phys. Rev. B, 20, 4577-4583 (1979). 79Yat: S.P. Yatsenko. A.A. Semyannikov, B.G. Semenov, and K.A. Chuntonov, J. Less-Common Met., 185-199 (1979). 80Bus: K.H.J. Buschow, H.A. Algra, and R.A. Henskens, J. Appl. Phys., 51(1), 561-566 (1980). 81Pel1: J. Pelleg and L. Zevin, J. Less-Common Met., 77, 197-203 (1981). 81Pel2: J. Pelleg, G. Kimmel, and D. Dayam, J. Less-Common Met., 81, 33-44 ( 1981). 84Gla: E.I. Gladyshevskii, Ya.P. Yarmolyuk, and Yu.N. Hryn, 13th Int. Congress Crystallogr., Hamburg, 1984.08-C243. 85Kim: G. Kimmel, D. Dayan, L. Zevin, and J. Pelleg, Metall. Trans., 16A, 167- 171 (1985). 86Tag: Y. Tagawa, J. Sakurai, and Y. Komura, J. Less-Common Met., 119, 269-275 (1986). 86Yat: S.P. Yatsenko, E.I. Gladishevskii, O.M. Sitschewitsch, V.K. Belsky, A.A. Semyannikov, Yu.N. Hryn, and Ya.P. Yarmolyuk, J. Less-Common Met., 115, 17-22 (1986). Published in Bull. Alloy Phase Diagrams, 11(1), Feb 1990. Complete evaluation contains 1 figure, 3 tables, and 33 references. Special Points of the Ga-Gd System