The Heusler-type alloy MgZn₂Ce

Abstract

Key indicators: single-crystal X-ray study; T = 295 K; mean (Ce-Mg) = 0.002 Å; R factor = 0.016; wR factor = 0.045; data-to-parameter ratio = 11.0.Single crystals of the MgZn 2 Ce alloy (magnesium dizinc cerium) were synthesized by a two-step method which couples the thermal treatment of pressed pellets of the pure elements with subsequent arc melting. The compound crystallizes in a Heusler-type (MnCu 2 Al) structure in the space group Fm3m, with one Zn site (site symmetry 43m), one Ce and one Mg site (both with m3m site symmetry). All interatomic distances indicate metallic type bonding.

The isothermal section of the phase diagram of Ce–Mg–Zn ternary system at 470 K

“…The last compound was found to crystallize with a cubic unit cell (a ¼ 7064 Å) whereas the crystal structures of the other above mentioned compounds remained unknown. In our previous works we reported about the crystal structures of cubic CeMgZn 2 (Fm-3m, a ¼ 7.0358(4) Å) [4], Ce 20 Mg 19 Zn 81 (F-43m, a ¼ 21.1979(8) Å) [5] and orthorhombic Ce 3 (Zn 0.863 Mg 0.137 ) 11 [6] ternary compounds.…”

Experimental study and thermodynamic assessment of ternary Mg–Zn–Ce phase relations focused on Mg-rich alloys

“…The decagonal quasicrystal reported in many of the Mg-Zn-RE systems was not observed in the Mg-Zn-Ce system [13]. Pavlyuk et al reported a Heusler-type alloy with the composition CeMgZn 2 [14] and a cubic phase Ce 20 Mg 19 Zn 81 [15]. Crystallographic data and compositions of all ternary phases accepted in the present study are summarized in Table 1.…”

“…They examined the solid solubilities of binary and ternary solutions by EDS and EPMA. In addition to the four ternary phases reported previously [6], two new ternary phases, Ce 2 Mg 53 Zn 45 and Ce 6 Mg (8)(9)(10)(11)(12)(13)(14)(15) Zn , were found in their work. The decagonal quasicrystal reported in many of the Mg-Zn-RE systems was not observed in the Mg-Zn-Ce system [13].…”

“…Also the phases T5, CeMgZn 2 , and Ce 20 Mg 19 Zn 81 reported by Refs. [14,15] were not considered in this work, focusing on the Mg-rich region. d At 350 C.…”

“…In order to prevent the vaporization of Mg and Zn, the samples were not prepared by arc-melting method, since the significant loss of these metals leads to substantial change of the compositions. The weighted elements were pressed carefully to pellets which were sealed under argon atmosphere by welding in [14] a The phases CeMg 3 and s 4 from the assessment of Kolitsch et al [7] were simplified to one phase, CeMg 3 . b The phases CeMg 12 and s 2 from the assessment of Kolitsch et al [7] were simplified to one phase, CeMg 12 .…”