2014/11/03 by Arvind Maurya, P. Bonville, Maurya, Arvind +5
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1411.0379
9 Pages and 9 Figures
arxiv created 2014/11/03 · openalex publication_date 2014/11/03 · arxiv updated 2014/11/04 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present detailed investigations in single crystals of two recently reported quaternary intermetallic compounds EuRhAl4Si2 and EuIrAl4Si2 employing magnetization, electrical resistivity in zero and applied fields, heat capacity and 151Eu Mössbauer spectroscopy measurements. The two compounds order antiferromagnetically at T\rm N1 = 11.7 and 14.7 K, respectively, each undergoing two magnetic transitions: the first from paramagnetic to incommensurate modulated antiferromagnetic, the second at lower temperature to a commensurate antiferromagnetic phase as confirmed by heat capacity and Mössbauer spectra. The magnetic properties in the ordered state present a large anisotropy despite Eu2+ being an S-state ion for which the single-ion anisotropy is expected to be weak. Two features in the magnetization measured along the c-axis are prominent. At 1.8 K, a ferromagnetic-like jump occurs at very low field to a value one third of the saturation magnetization (1/3 M0) followed by a wide plateau up to 2 T for T = Rh and 4 T for T = Ir. At this field value, a sharp hysteretic spin-flop transition occurs to a fully saturated state (M0). Surprisingly, the magnetization does not return to origin when the field is reduced to zero in the return cycle, as expected in an antiferromagnet. Instead, a remnant magnetization 1/3 M0 is observed and the magnetic loop around the origin shows hysteresis. This suggests that the zero field magnetic structure has a ferromagnetic component, and we present a model with up to third neighbor exchange and dipolar interaction which reproduces the magnetization curves and hints to an "up-up-down" magnetic structure in zero field.