TY  - JOUR
AU  - Peter, Sebastian C.
AU  - Disseler, Steven M.
AU  - Niclas Svensson, J.
AU  - Carretta, Pietro
AU  - Graf, Michael J.
TI  - Yb<sub>4</sub>LiGe<sub>4</sub> – A Yb mixed valent Zintl phase with strong electronic correlations
JO  - Journal of alloys and compounds
VL  - 516
SN  - 0925-8388
CY  - Lausanne
PB  - Elsevier
M1  - PUBDB-2018-00890
SP  - 126 - 133
PY  - 2012
N1  - © Elsevier B.V. ; Post referee fulltext in progress; Embargo 12 months from publication
AB  - Single-phase samples of Yb<sub>4</sub>LiGe<sub>4</sub> and Yb<sub>5</sub>LiGe<sub>4</sub> were synthesized using high frequency (HF) heat treatment. Yb<sub>4</sub>LiGe<sub>4</sub> crystallizes in orthorhombic space group Pnma with the Gd<sub>5</sub>Si<sub>4</sub> type of crystal structure and lattice parameters a = 7.0828(3) Å, b = 14.6415(7) Å, and c = 7.6279(4) Å. One Yb position in Yb<sub>5</sub>LiGe<sub>4</sub> is substituted by the lithium atom and causes a distortion of the germanium tetragons in Yb<sub>4</sub>LiGe<sub>4</sub>. Investigation of the electronic state of Yb via magnetic susceptibility and X-ray absorption near-edge spectroscopy (XANES) revealed a presence of two electronic states of ytterbium, 4f<sup>13</sup> and 4f<sup>14</sup> (mixed valence), in Yb<sub>5</sub>LiGe<sub>4</sub> and Yb<sub>4</sub>LiGe<sub>4</sub>. Studies of the temperature dependence of the electrical resistivity, magnetization, 7Li spin-lattice relaxation rate and the specific heat indicate that strong electronic correlations are present in Yb<sub>4</sub>LiGe<sub>4</sub>, and below approximately 50 K there is a competition between ferromagnetic and antiferromagnetic correlations. Magnetic ordering in Yb<sub>4</sub>LiGe<sub>4</sub>, if present, occurs below the reported antiferromagnetic transition temperature of 1.7 K for Yb<sub>5</sub>LiGe<sub>4</sub>.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000299106600023
DO  - DOI:10.1016/j.jallcom.2011.11.148
UR  - https://bib-pubdb1.desy.de/record/399738
ER  -