Abstract
We report a polarized neutron-diffraction study conducted to reveal the nature of the weak ferromagnetic moment in the superconducting ferromagnet UCoGe. We find that the ordered moment in the normal phase in low magnetic fields is predominantly located at the U atom and has a magnitude of at 3 T, in agreement with bulk magnetization data. By increasing the magnetic field the U moment grows to in 12 T and most remarkably, induces a substantial moment on the Co atom directed antiparallel to the U moment. The anomalous polarizability of the orbitals is unique among uranium intermetallics and might reflect the proximity to a magnetic quantum critical point of UCoGe in zero field.
- Received 7 May 2010
DOI:https://doi.org/10.1103/PhysRevB.81.180407
©2010 American Physical Society