O. V. Emelianova | Searcharxiv

arXiv2022

Antiferromagnetic resonances in twinned EuFe2As2 single crystal

In this work, we report ferromagnetic resonance spectroscopy of EuFe2As2 single crystals. We observe ferromagnetic resonance responses, which are attributed to antiferromagnetic resonances of Eu sub-lattice with orthorhombic crystal structure and with different orientations of twin domains relative to the external field. We confirm validity of the recently-proposed spin Hamiltonian with anisotropic Eu-Eu exchange interaction and biquadratic Eu-Fe exchange interaction.

cond-mat.supr-con↗

arXiv2021

Helical spin order in EuFe2As2 and EuRbFe4As4 single crystals

In this work, fabrication and characterization of magnetic properties of EuFe2As2 and EuRbFe4As4 single crystals is reported. Magnetization measurements of samples with well defined thin film geometry and crystal orientation demonstrate a striking similarity in ferromagnetic properties of Eu subsystems in these two compounds. Measurements with magnetic field applied along ab crystal planes reveal meta-magnetic transition in both compounds. Numerical studies employing the Jz1-Jz2 Heisenberg model suggest that the ground state of the magnetic order in Eu subsystem for both compounds is the helical spin order with the helical angle about 2pi/5, while the meta-magnetic transition is the helix-to-fan first order phase transition.

cond-mat.supr-con↗