Magnetic structures of geometrically frustrated SrGdO derived from powder and single-crystal neutron diffraction
arXiv:2201.01176 · doi:10.1103/PhysRevB.105.014425
Abstract
We present the low-temperature magnetic structures of SrGdO combining neutron diffraction methods on polycrystalline and single-crystal samples containing the Gd isotope. In contrast to other members of the SrO family ( = lanthanide) this system reveals two long-range ordered magnetic phases, which our diffraction data unambiguously identify. Below = 2.73~K, a = (0 0 0) magnetic structure is stabilized where ferromagnetic chains along the ~axis (space group ) are coupled antiferromagnetically with neighboring chains. On cooling below = 0.48~K, an additional incommensurate component modulated by = (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.