Room-Temperature Magnetic Skyrmions and Intrinsic Anomalous Hall Effect in a Nodal-Line Kagomé Ferromagnet MnRhP

Topological magnetic semimetals with kagomé lattices have attracted significant attention due to their nontrivial electronic band structures and pronounced electromagnetic responses. The search for kagomé-lattice topological semimetals exhibiting magnetic ordering above room temperature is essential for advancing their potential in device applications. In this work, we report direct observations of topological magnetic textures and anomalous Hall effects driven by topological nodal lines in MnRhP, a room-temperature ferromagnet with a distorted kagomé lattice. 

Using single-crystal magnetization measurements and powder neutron diffraction, we reveal a weak uniaxial magnetic anisotropy. Lorentz transmission electron microscopy observations confirm the presence of stable magnetic skyrmions above room temperature. Moreover, both the ordinary and anomalous Hall effects are significantly enhanced upon cooling, with a large anomalous Hall conductivity (AHC) observed at low temperatures. First-principles calculations indicate significant contributions to electronic states near the Fermi level from both in-plane and out-of-plane d orbitals of Mn and Rh, resulting in the low magnetic anisotropy energy. The calculated Berry curvature reproduces the experimentally observed large AHC, providing direct evidence for an intrinsic mechanism linked to the topological nodal lines. These findings establish MnRhP as a promising kagomé-lattice magnet for investigating topological magnetic textures and anomalous transport phenomena at room temperature.