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TT: Fachverband Tiefe Temperaturen

TT 80: Correlated Electrons: Poster

TT 80.6: Poster

Thursday, March 21, 2024, 15:00–18:00, Poster E

Single crystal growth and characterization of EuMn₂Si₂ and EuMn₂Ge₂ — •Janina Strahl, Marwa Hussein Abdelhakam Abouelela, Kristin Kliemt, and Cornelius Krellner — Institute of Physics, Goethe-University, Frankfurt (Main), Germany

EuMn₂Si₂ exhibits a thermally driven valence transition at around 530 K of the europium ions above room temperature from Eu³⁺ at low temperatures to Eu^{∼ 2.5+} at high temperatures [1]. The isoelectronic and isostructural substitution of silicon with germanium leads to a stabilization of the divalent state of Eu in EuMn₂Ge₂ without Eu ordering down to 1.5 K [1]. Both rare earth intermetallic 122 compounds crystallize in the tetragonal ThCr₂Si₂ structure type and show antiferromagnetic ordering of the manganese sublattices above room temperature. In literature [1,2] additional spin-reorientation transitions in polycrystalline samples at low temperatures were observed. In this contribution, we present the single crystal growth of these compounds and the results of our structural, chemical and magnetic characterization.
[1] M. Hofmann et al., Phys. Rev. B 69, 174432 (2004)
[2] I. Nowik et al., Phys. Rev. B 55, 3033 (1997)

Keywords: crystal growth; valence fluctuation; antiferromagnetism