I. Mirebeau et N. Martin, J. Appl. Cryst. (2022). 55, 1173-1183
The application is discussed of neutron methods to the study of reentrant spin glasses (RSGs), close to the transition towards a `canonical' spin glass (SG). The focus is on two emblematic systems, namely Au1−xFex and amorphous a-Fe1−xMnx. A set of experimental results is presented to highlight their peculiar static and dynamic properties. The role of small-angle neutron scattering (SANS) is stressed as an important tool to unravel the structure of these complex systems over mesoscopic length scales. Finally, recent SANS results performed under an applied magnetic field in the region of the RSG → SG transition are presented. They show that vortex-like defects are present in the RSG region up to the critical line and vanish in the SG region. These defects, which develop only in a ferromagnetic medium, could be a key feature to probe the emergence of long-range magnetic order.
• Physics, chemistry, nanoscience and materials around large instruments › Physique de la matière condensée, étude par l’interaction rayonnement matière Physique, chimie, nanosciences et matériaux autour des grands instruments
• Laboratoire Léon Brillouin (LLB) • Leon Brillouin Laboratory (LLB)
• Nouvelles frontières dans les matériaux quantiques - NFMQ • Small angle scattering
• Neutrons • Activités instrumentales nationales et internationales du LLB - National and internatonial instrumental activities at the LLB • Neutrons • Small Angle Neutron Scattering (PA)