Crystallographic and magnetic structure of UNi${}_4$${}^{11}$B

Abstract

We present an extensive powder and single-crystal neutron scattering investigation of the crystallographic structure and magnetic order of the frustrated metallic $f$-electron magnet UNi${}_4$B. We carry out a full refinement of the crystallographic structure and conclude that the low-temperature lattice symmetry is orthorhombic (space group Pmm2; cell parameters: $a=6.963(4)\mathring{A}$ , $b=14.793(9)\mathring{A}$ , $c=17.126(8)\mathring{A}$). We determine the magnetically ordered structure, concluding that below $T_{\mathrm{N}}=19.5\mathrm{K}$ the material undergoes a transition into a partially ordered antiferromagnetic state. The magnetic structure is consistent with the existence of toroidal order in this material. We further test the proposal of a second magnetic transition occurring at $330\mathrm{mK}$, concluding that the thermodynamic anomalies observed at these temperatures do not reflect modifications of the magnetic structure. Our study provides a consistent picture of the interrelationship of structural and magnetic properties in the frustrated magnet UNi${}_4$B previously unresolved.

Submitted to Phys. Rev. B

References in corpus (4)

• Spin Chirality in a Molecular Dysprosium Triangle: the Archetype of the Non-Collinear Ising Model
• Toroidal order in metals without local inversion symmetry
• Hyperfine Interactions in the Heavy Fermion CeMIn_5 Systems
• Electric Quadrupolar Contributions in the Magnetic Phases of UNi${}_4$B

Cited by in corpus (1)

• Spin-orbital-momentum locking under odd-parity magnetic quadrupole ordering