EuPd2Si2 is a valence-fluctuating system undergoing a temperature-induced valence crossover at TV′≈160K. We present the successful single crystal growth using the Czochralski method for the substitution series EuPd2(Si1−xGex)2, with substitution levels x≤0.15. A careful determination of the germanium content revealed that only half of the nominal concentration is build into the crystal structure. From thermodynamic measurements it is established that TV′ is strongly suppressed for small substitution levels and antiferromagnetic order from stable divalent europium emerges for x≳0.10. The valence transition is accompanied by a pronounced change of the lattice parameter a of order 1.8%. In the antiferromagnetically ordered state below TN=47 K, we find sizeable magnetic anisotropy with an easy plane perpendicular to the crystallographic c direction. An entropy analysis revealed that no valence fluctuations are present for the magnetically ordered materials. Combining the obtained thermodynamic and structural data, we construct a concentration-temperature phase diagram demonstrating a rather abrupt change from a valence-fluctuating to a magnetically-ordered state in EuPd2(Si1−xGex)2.
@article{arxiv.2303.07472,
title = {From valence fluctuations to long-range magnetic order in EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ single crystals},
author = {Marius Peters and Kristin Kliemt and Michelle Ocker and Bernd Wolf and Pascal Puphal and Matthieu Le Tacon and Michael Merz and Michael Lang and Cornelius Krellner},
journal= {arXiv preprint arXiv:2303.07472},
year = {2023}
}