Investigating The Magnetic Structure of Single Crystal YBaCuFeO₅ by Neutron and X-ray Scattering

Yu-Hui Liang^1*, Chun-Hao Lai¹, Chin-Wei Wang², Shin-ichiro Yano², Kirrily C Rule³, Daisuke Okuyama⁴, Yen-Chung Lai⁵, Wei-Tin Chen⁶, Chao-Hung Du¹

¹Department of Physics, Tamkang University, New Taipei City, Taiwan
²Neutron Group, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
³Australian Center for Neutron Scattering, Australian Nuclear Science and Technology Organization, NSW, Australia
⁴Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
⁵Materials Science Group, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
⁶Center for Condensed Matter Sciences, National Taiwan University, Taipei City, Taiwan

* Presenter:Yu-Hui Liang, email:yhl050893@gms.tku.edu.tw

Multiferroics has been extensively studied because it plays as an important platform for studying the cross-coupling between the different electronic degrees of freedom in the crystal space, such as spin, orbital, charge, and lattice. Using magnetization we observed that single-crystal YBaCuFeO₅ (YBCFO), which grows by modified floating zone method, exhibits two antiferromagnetic transitions at T_N1 ∼ 455 K and T_N2 ∼ 175 K. Below T_N2 the magnetic structure transforms from commensurate into an ab-spin spiral magnetic structure with a propagation vector of (h/2 k/2 l/2±δ) and the δ is depending on temperature. In addition, from field-dependent AC susceptibility measurement we found an unusual domain structure behavior. In order to establish the mechanism, using elastic neutron scattering. The results indicate that strong magnetic coupling between different magnetic phases due to the strong interactions between Fe and Cu spins and YBCFO forms more domains with decreasing field or temperature. By using resonant x-ray scattering to confirm the mechanisms of the magnetic structure. We speculate that the spiral magnetic structure at low temperature is a double helix, composed of Fe/Cu, and form new helix structures with decreasing field or temperature.

Keywords: Magnetic Structure, Elastic Neutron Scattering, Resonant Elastic X-ray Scattering