The chiral anomalous Hall effect at high magnetic fields in Au-Fe alloys

ABSTRACT

The Hall effect of the disordered and frustrated magnetic alloys Au-Fe 8 at% and Au-Fe 18 at% was studied in applied magnetic fields up to 14 T. The measurements were carried out in fixed temperatures spanning the spin glass and paramagnetic phases of Au-Fe 8 at% and in the reentrant, ferromagnetic and paramagnetic states in Au-Fe 18 at%. The experiments confirm the occurrence of a large contribution from spin chiralities to the anomalous Hall effect (AHE) in both systems, either in the spin glass and the canted ferromagnetic phases. The amplitude of the chirality-driven term is progressively attenuated as the field intensity is increased. This effect is consistent with the expected field-induced closing of the solid angle defining scalar spin chirality. Evidence for the occurrence of a chiral contribution to AHE was also detected in the paramagnetic phases of the two studied systems, showing that this term persists as long as the typical time scale for the spin dynamics is significantly larger than the transport relaxation time.

KEYWORDS:

• Anomalous Hall effect
• spin glass
• reentrant magnetic system
• spin chirality

Acknowledgments

A portion of this work was performed at the National High Magnetic Field Laboratory, Los Alamos National Laboratory, USA, which is supported by the U.S. National Science Foundation, U.S. Department of Energy and the State of Florida. The authors also acknowledge Dr Fabiano Mesquita for a careful revision of the text.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partially financed by the Brazilian agencies Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) [grant PRONEX 16/0490-0].