We present the low-temperature magnetic structures of SrGd2O4 combining neutron diffraction methods on polycrystalline and single-crystal samples containing the 160Gd isotope. In contrast to other members of the SrLn2O4 family (Ln = lanthanide) this system reveals two long-range ordered magnetic phases, which our diffraction data unambiguously identify. Below TN1 = 2.73~K, a q1 = (0 0 0) magnetic structure is stabilized where ferromagnetic chains along the c~axis (space group Pnam) are coupled antiferromagnetically with neighboring chains. On cooling below TN2 = 0.48~K, an additional incommensurate component modulated by q2 = (0~0~0.42) evolves and aligned along either of the perpendicular axes for the two different Gd sites, resulting in a fan-like magnetic structure. The identification of the particular Gd sites with the magnetic order observed with neutron diffraction is facilitated by a detailed analysis of the crystal fields acting on the sites. The observed ordering phenomena underline the complex multiaxial anisotropy in this system.
@article{arxiv.2201.01176,
title = {Magnetic structures of geometrically frustrated SrGd$_2$O$_4$ derived from powder and single-crystal neutron diffraction},
author = {N. Qureshi and B. Z. Malkin and S. X. M. Riberolles and C. Ritter and B. Ouladdiaf and G. Balakrishnan and M. Ciomaga Hatnean and O. A. Petrenko},
journal= {arXiv preprint arXiv:2201.01176},
year = {2022}
}