Low-Temperature Physical Properties of Single-Crystalline EuCoGe₃and EuRhGe₃

Abstract

Since a few years europium-based intermetallics have been attracting more and more attention due to their intriguing physical properties with anomalous behaviours in magnetically ordered states. Here, we report on the formation and the bulk physical properties of two tetragonal compounds EuCoGe3 and EuRhGe3, studied on high-quality single-crystalline specimens. In both materials, the Eu ions are in their divalent state, which gives rise to an antiferromagnetic ordering below TN = 15.4 K and TN = 11.3 K, respectively. In addition, EuCoGe3 exhibits a successive antiferromagnetic phase transition at T2 = 13.4 K. Based on some characteristic features in the temperature variations of the magnetic susceptibility, specic heat and electrical resistivity, we suggest that in both germanides an amplitude modulated magnetic structure develops below the respective TN, with the Eu magnetic moments directed along the crystallographic [001] axis in EuCoGe3 and perpendicular to this direction in EuRhGe3.

Magnetic properties of EuCr2Al20

“…A characteristic feature of this function is a pronounced hump located near T /3 N that can be assigned to Zeeman splitting of the ground state multiplet 8 S 7/2 of Eu 2 þ ions in molecular magnetic field that acts in the magnetically ordered state [31,33]. Previously, similar anomaly was observed for several Eu-based compounds, like for example EuB 6 [32], EuCu 2 As 2 and EuCu Sb 1.82 2 [33], EuRh 2 Si 2 [34], EuRh 2 Ge 2 [26], or the series EuTGe 3 (T ¼Co, Ni, Rh, Pd, Ir, Pt) [25,35,36]. The low-temperature maximum in Δ ( ) C T T / found for EuCr 2 Al 20 is however much smaller than the MFA prediction.…”

The Magnetic Field Induced Ferromagnetism in EuPd2Sn4 Novel Compound

“…Such a broad shoulder, seen at around one‐fourth of , is typical for systems ( and ) and is related to the large degeneracy of the local moment within the mean‐field theory for a ()‐fold degenerate multiplet. [ 13,21,22 ]…”

Strongly anisotropic and complex magnetic behavior in EuRhGe3

“…A preliminary account on this research was given in a conference article [15]. Here, we report for the first time on the strongly anisotropic magnetic behavior of the compound evidenced in magnetic susceptibility, magnetization, heat capacity, and electrical resistivity measurements, carried out down to 0.4 K in magnetic fields up to 9 T. Based on the obtained data, the magnetic BÀT phase diagrams were constructed for the two characteristic directions in the tetragonal unit cell of EuRhGe 3 .…”