Crystal structure and electronic properties of the new compounds U3Co12−xX4 with X=Si, Ge

Characterization of the novel intermetallic compounds U2Co3Ge, U6Co12Ge4 and U6Co12Ge4C

“…The two ternary compounds show Pauli paramagnetic behavior with their temperature independent magnetic susceptibility of about 2 × 10 −3 emu mol U −1 . Similar magnitude of the susceptibility was reported for the binaries UCo [33] and UCo 1.981 [34] and the ternaries UCo 2.6 Ge 0.4 [14] and U 3 Co 12−x Ge 4 [13], which also behave as Pauli paramagnets. Remarkably, in all these phases the ratio of the number of Co atoms over the total number of atoms is between 1/2 and 2/3.…”

“…Both materials exhibit a metallic character of the electronic transport. The bending over the (T) dependencies likely signals some contribution to the carriers scattering due to spin fluctuations [37,38], as previously reported for example for U 3 Co 12−x Ge 4 [13].…”

“…Up to now, eight ternary intermetallic phases have been reported in the literature, namely UCoGe [7], UCo 2 Ge 2 [8], UCo 6 Ge 6 [9], U 3 Co 2 Ge 7 [10], U 3 Co 4 Ge 7 [11], U 2 Co 17−y Ge y (1.3 ≤ y ≤ 3) [12], and the newly characterized intermediate compounds, U 3 Co 12−x Ge 4 (0 ≤ x ≤ 2) [13] and UCo 3−x Ge x (0.2 ≤ x ≤ 0.4) [14]. Recently, we have identified two novel ternaries U 2 Co 3 Ge and U 6 Co 12−x Ge 4 , which adopt a ternary ordered variant of the MgZn 2 Laves phase [15] (Mg 2 Cu 3 Si-type structure [16]) and a ternary derivative of the Ca 3 Ag 8 structure [17] (Ce 3 Ni 6 Si 2 -type [18]), respectively.…”

On the ternary RE Mg1–Al2 (RE = Gd – Tm), RE3Ag5±Mg11±, REAg4+Mg2–, RE4Ag10.3Mg12 and RE4Ag10+Mg3– (RE = Ce – Nd, Sm) phases

“…Further investigation among the phases with the Gd 3 Ru 4 Al 12 type were focused on the Fe-and Co-aluminides and extended from lanthanides to actinides [40][41][42][43][44][45][46][47]. Recently, two representatives (U 3 Co 12-x Si 4 and U 3 Co 12-x Ge 4 ) of the slightly deformed and defected Gd 3 Ru 4 Al 12 type were reported in [48]. It should be underlined that among the rare earth -transition metal -magnesium systems only one phase, i.e.…”

Magnetocaloric properties of a novel ferromagnet Gd3Co4+xAl12−x (x = 0.50)

“…A short discussion about the structural relationship in EuMg 5.7 -derivatives (including Gd 3 Ru 4 Al 12 ) can be found in Ref. [17]. Within this structurally related family, a large variety of possible occupancies/substitutions exists on the non-rare earth element sites and the 2b site is partly occupied by the transition metal in the case of U 3 Co 12Àx Al 4 , partly occupied by Mg in EuMg 5.2 , and fully occupied by the p-block element in Sc 3 Ni 11 Si 4 or Gd 3 Ru 4 Al 12 .…”