Rare earth–transition metal–magnesium compounds—An overview

The ternary system Yb–Cu–Mg: Isothermal section at 400°C in the range from 0 to 67at.% Cu

“…On the same Cu-concentration line a ternary ordered variant of the Laves phase with MgCu 4 Sn-type forms, s 2 -(Yb 1Àx Mg x )Cu 2 , with a homogeneity region extending from 15 to 21 at.% Mg, including the compound YbCu 4 Mg found earlier with full atom order [12]. It is interesting to note that the phase with the MgCu 4 Sn-type superstructure seems to exist between w64 and 67 at.% Cu with a small deviation from the stoichiometric formula Phase equilibria in the middle part of the Yb-Cu-Mg isothermal section at 400 C are characterized by the existence of a new ternary phase (s 3 ) whose composition corresponds to the stoichiometry Yb 2 Cu 2 Mg, which often occurs in similar RE-T-Mg systems [2]. Phase s 3 has been found to form two-and three-phase equilibria involving Yb(Cu x Mg 1Àx ) 2 , YbCu and s 2 -(Yb 1Àx Mg x )Cu 2 (see Samples prepared on (or near) the 2:2:1 stoichiometry and analyzed in different conditions (as-cast, after DTA, after slow cooling or after annealing) show a microstructure similar to that reported in Fig.…”

“…Although research activities throughout the recent years have provided a wealth of information on phase diagrams, compound formation and crystal chemistry of RE-T-Mg (T ¼ transition metal) systems [2,3], little is known yet about the constitution of alloy systems with ytterbium. With respect to the small energy separation of the Yb 2þ / Yb 3þ ground states, ytterbium forms a series of intermetallic compounds with mixed and/or intermediate valence behaviour (f 13 -f 14 ).…”

Phase Transformation and Hydrogen Storage Properties of an La7.0Mg75.5Ni17.5 Hydrogen Storage Alloy

“…Its crystal structure was drawn with Diamond 3.0 software in Figure 1. It can be seen that the La 7.0 Mg 75.5 Ni 17.5 alloy had a multiphase structure containing an LaMg 2 Ni phase with a CuMgAl 2 -type structure [16][17][18] relatively low hydrogen desorption temperature and fine kinetic properties [14]. However, the hydrogen storage capacity of this alloy was dramatically reduced by excessive un-hydrogenation elements such as La and Ni.…”

“…Its crystal structure was drawn with Diamond 3.0 software in Figure 1. It can be seen that the La7.0Mg75.5Ni17.5 alloy had a multiphase structure containing an LaMg2Ni phase with a CuMgAl2-type structure [16][17][18], an La2Mg17 phase with an Ni17Th2-type structure, and an Mg2Ni phase. No La-Ni phase was observed, which is ascribed to the abundant Mg atoms in the alloy; thus, the La and Ni atoms are a solid solute and readily alloy with the Mg. Figure 2 shows the SEM micrographs of the La 7.0 Mg 75.5 Ni 17.5 alloy, and its EDS analysis is listed in Table 2.…”

Combined Effects of Lanthanum(III) and Elevated Ultraviolet-B Radiation on Root Nitrogen Nutrient in Soybean Seedlings

“…Rare earth elements (REEs) have been widely used in metallurgical machinery, the petroleum chemical industry, glass ceramics, textile and light industry, new materials, and other fields because of their unique physical-chemical properties [1][2][3][4][5][6][7][8]. REE-based applications in various fields over a long period and large-scale REE mining activities have increased the REE content in the environment [9][10][11][12][13][14][15].…”