Structural transition and antiferromagnetic ordering in the solid solution CePd_1−x Au _x Al (x = 0.1–0.9)

Abstract

The intermetallic solid solution CePd1−xAuxAl (x = 0.1–0.9) has been synthesized from the elements by arc-melting and subsequent annealing in induction followed by tube furnaces. The samples were characterized using the Guinier powder diffraction technique and the structures of the nominal compositions CeAuAl and CePd0.2Au0.8Al were refined from single crystal X-ray diffractometer data. For small values of x = 0.1–0.3, the compounds crystallize in the hexagonal ZrNiAl-type structure (space group P$‾{6}$2m), while for x = 0.5–0.9 the orthorhombic TiNiSi-type structure (space group Pnma) was observed. In both structure types, the transition metal and aluminum atoms form a complex polyanionic network with the cerium atoms filling the respective cavities. The transition metal atoms are in both cases surrounded in the shape of a tri-capped trigonal prism, the connectivity of these units, however, is different. Temperature-dependent magnetic susceptibility measurements of all compounds indicated a stable trivalent oxidation state for the cerium atoms along with antiferromagnetic ordering around TN ∼ 3 K.

Electronic and structural properties of Y6Pt13X4, site occupancy variants of the Ba6Na16N subnitride (X = Al, Ga)

“…Ternary rare earth (RE) transition metal (T) aluminides and gallides have hitherto been the subjects of active research efforts as part of a search for materials exhibiting interesting structural, magnetic and transport properties. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Among the advances of the last decade, one should mention the extensive structural studies for the series (i) RE 10 TAl 3 , 18 RE 4 TAl 19,20 and Ho 6 Co 2 Ga-type compounds 21 and (ii) RE 4 T 9 Al 24 , 22 RE 2 T 6 Al 15 and RE 3 T 4 Al 12 , 23,24 RETAl 2 25 for the RE-rich and Al (or Ga)rich compounds, respectively as well as the numerous investigations of their responses to electrical and magnetic stimuli. [26][27][28][29][30] Significantly less ternary RE aluminides and gallides are known for the transition metal-rich concentration range, particularly with platinum as a transition metal substitute (Pt ≥ 50 at%).…”