On Ternary Intermetallic Aurides: CaAu₂Al₂, SrAu_2–xAl_2+x and Ba₃Au_5+xAl_6–x

Abstract

Abstract. The intermetallic compound CaAu 2 Al 2 , and the members of the solid solutions SrAu 2-x Al 2+x (0 Յ x Յ 0.33) and Ba 3 Au 5+x Al 6-x (x = 0, 0.14, 0.49) were synthesized from the elements in sealed tantalum ampoules. The Ca compound crystallizes with the orthorhombic ThRu 2 P 2 type structure, whereas the targeted SrAu 2 Al 2 was found to form a solid solution according to SrAu 2-x Al 2+x . For the Ba system no "BaAu 2 Al 2 " was found, however, Ba 3 Au 5+x Al 6-x was discovered to crystallize in the monoclinic space group C2/c with its own structure type. The samples were investigated by powder X-ray diffraction and their crystal structures were refined on the basis of single-crystal

Extending the knowledge on the quaternary rare earth nickel aluminum germanides of the RENiAl4Ge2 series (RE=Y, Sm, Gd–Tm, Lu) – structural, magnetic and NMR-spectroscopic investigations

“…Furthermore, the significant difference in the isotropic magnetic (de-)shielding contributions, δ iso ms , between Al1 and Al2 signifies a large difference between the s-density of states (s-DOS) at the Fermi level for these two aluminum species. While the values measured for Al1 are comparable to those obtained in numerous other intermetallic compounds [18,20,22,75], resulting in a substantial Knight shift contribution, Simulation of the spectra of Figure 9 right (method 1). b F1/F2 Center of gravity analysis of the TQ spectra (method 2).…”

“…Due to our interest in the crystal structures and the physical and NMR spectroscopic properties [18] of intermetallic aluminum compounds of the alkali (Na 2 Au 3 Al [19]), alkaline earth (e.g. MAu 2 Al 2 with M = Ca, Sr [20]; MAuX with M = Ca-Ba and X = Al-In [21]; MPtAl 2 with M = Ca-Ba [22]) and the rare earth elements (e.g. RET 5 Al 2 with RE = Y, Gd-Tm, Lu and T = Pd, Pt [23], RE 2 TAl 3 with RE = Y, La-Nd, Sm, Gd-Lu and T = Ru, Rh, Ir [24], Eu 2 Pt 6 Al 15 [25], Eu 2 Ir 3 Al 9 [26] or YbPd 2 Al 3 [27]), the interest of extending the knowledge of quaternary aluminum containing compounds has sparked.…”

Raman and NMR spectroscopic and theoretical investigations of the cubic laves-phases REAl2 (RE = Sc, Y, La, Yb, Lu)

“…27 And although this class of compounds has metallic character, the method can be used to gain a plethora of information such as validation of crystallographic structures, local environments, solid solutions and more. And although many ternary compounds have been characterized by NMR (e. g. the equiatomic ScTAl compounds, 28 the ScT 2 Al Heusler phases, 29 the gold compounds Na 2 Au 3 Al, 30 AEAuX, 31 AEAu 2 Al 2 , 32 or the platinides Ba 3 Pt 4 Al 4 33 or Sr 2 Pt 3 Al 8 34 ) there is a significant lack of comparing studies about a larger group of isostructural compounds. As examples for the latter, the MTAl 2 35,36 or the RE 10 TAl 3 series 37 should be mentioned.…”

Temperature induced valence phase transition in intermediate-valent YbPd2Al3

“…Na 2 Au 3 Al, 58 AEAuX (AE ¼ Ca-Ba, X ¼ Al-In), 59 AEAu 2 Al 2 (AE ¼ Ca, Sr) 60 2 Since the most electronegative elements acquire additional electron density, a shi towards lower binding energies can be observed in the respective XPS measurements. [58][59][60][61] Fig (green), Yb 0.33 Ca 0.67 Pd 2 Al 3 (blue), and CaPd 2 Al 3 (orange). As can be seen from the plot and the data in Table 2, only minor shi of the 3d 5/2 and 3d 3/2 lines of the Pd reference and the investigated compounds can be observed.…”