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N. Nasir, N. Melnychenko-Koblyuk, A. Grytsiv, P. Rogl, E. Bauer, E. Royanian, H. Michor, G. Hilscher, G. Giester:
"Crystal structure and physical properties of EPCo_4.7Ge₉ (EP = Sr, Ba, Eu)";
Intermetallics, 17 (2009), 471 - 476.

BaCo4.7Ge9 (BaCo5−xGe9, x = 0.29) is a novel ternary compound which forms incongruently from the melt and crystallizes in a unique structure type (space group Pnma; a = 1.39910(2), b = 0.40218(2), c = 1.69882(2) nm, Z = 4). Isotypic compounds were found with SrCo4.7Ge9 (a = 1.39389(8), b = 0.39665(1), c = 1.67860(9) nm) and EuCo4.7Ge9 (a = 1.3910(1), b = 0.39425(2), c = 1.6741(2) nm). Physical properties (electrical resistivity, specific heat, magnetic susceptibility) were studied for BaCo4.7Ge9 and EuCo4.7Ge9. BaCo4.7Ge9 shows metallic behaviour but neither a superconducting nor a magnetic phase transition was observed for temperatures as low as T = 2 K. Magnetic susceptibility and specific heat data of EuCo4.7Ge9, evidence the onset of antiferromagnetic order at 18.5 K. Both magnetic ordering and the effective magnetic moment derived verify the Eu2+ state with a total angular momentum j = 7/2.

Rare-earth intermetallics, Crystallography, Electrical resistance, Magnetic properties, Site occupancy

http://dx.doi.org/10.1016/j.intermet.2008.12.010

http://dx.doi.org/10.1016/j.intermet.2008.12.010