Terahertz spectroscopy of antiferromagnetic resonances in YFe1-xMnxO3 (0 <= x <= 0.4) across a spin reorientation transition

Abstract

We have conducted a terahertz spectroscopic study of antiferromagnetic resonances in bulk orthoferrite YFe1-xMnxO3 0 <= x <= 0.4. Both the quasi-ferromagnetic resonance mode and the quasi-antiferromagnetic resonance mode in the weak ferromagnetic Gamma(4) phase disappear near the spin reorientation temperature, T-SR, for the onset of the collinear antiferromagnetic Gamma(1) phase (x >= 0.1). Below T-SR, an antiferromagnetic resonance mode emerges and exhibits a large blueshift with decreasing temperature. However, below 50 K, this mode softens considerably, and this tendency becomes stronger with Mn doping. We provide a deeper understanding of such behaviors of the antiferromagnetic resonance modes in terms of the influence of the Mn3+ ions on the magnetocrystalline anisotropy. Our results show that terahertz time-domain spectroscopy is a useful, complementary tool in tracking magnetic transitions and probing the interaction between disparate magnetic subsystems in antiferromagnetic materials with multiple ionic species.(c) 2021 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).