Symmetric hysteresis curves of rare earth-cobalt magnets measured by high magnetic fields

SmCo5magnets show generally asymmetrical hysteresis curves in the region of ordinary magnetic field strength. However, if these magnets are magnetized by a field of over 14 T, hysteresis loop becomes symmetric, except for the experimental errors caused by the thermal fluctuation after effect. The influence of the after effect on the magnetization curve and the coercive forceIHCare discussed.</p

LES CARACTÈRES DU MAGNÉTISME ITINÉRANT DES ALLIAGES FER-NICKEL ET FER-NICKEL-MANGANÈSE SOUS CHAMPS MAGNÉTIQUES FORTS

La susceptibilité sous champs forts, entre 30 000 et 80 000 Oe, de quelques alliages Invar, fer-nickel et fer-nickel-manganèse, à structure cubique faces centrées, a été déterminée aux basses températures soit par mesure directe, soit par extrapolation. Les résultats montrent un accord avec les valeurs calculées d'après Shimizu et al. suivant un modèle de bandes.The high field susceptibility, between 30 and 80 kOe and at low temperature, has been determined for iron-nickel and iron-nickel-mangan Invar alloys, with face centered cubic structure, by direct measurement or by extrapolation. The results show an agreement with the calculated values by Shimizu and al. according to a band model

Symmetric hysteresis curves of rare earth-cobalt magnets measured by high magnetic fields

SmCo5magnets show generally asymmetrical hysteresis curves in the region of ordinary magnetic field strength. However, if these magnets are magnetized by a field of over 14 T, hysteresis loop becomes symmetric, except for the experimental errors caused by the thermal fluctuation after effect. The influence of the after effect on the magnetization curve and the coercive forceIHCare discussed.</p

The Grenoble High Magnetic Field Laboratory as a USER FACILITY

The Grenoble High Magnetic Field Laboratory (GHMFL), run jointly by the Centre National de la Recherche Scientifique (C.N.R.S, France) and the Max-Planck Gesellschaft (MPG, Germany) is a leading laboratory pursuing research in the highest static magnetic fields technically feasible. The laboratory maintains strong in-house research activities and partly operates as a user facility for qualified external researchers. It has developed highly sophisticated instrumentation for specific use under high magnetic fields, including transport, magnetization, visible and infrared optical measurements at low temperatures and/or high pressures, EPR and NMR investigations in high magnetic fields. The laboratory delivers around 5000 hours of magnet time per year. Access for users to the high magnetic field facility is supported by the European Union, in the framework of the Human Potential Program: "Transnational Access to Major Research Infrastructures." We give an overview of the technical aspects of the facility and of the laboratory activities as a facility over the last years. The general organization of the user community and repartition between countries will be also reviewed

The Grenoble high magnetic field laboratory as a user facility

The Grenoble High Magnetic Field Laboratory is one of the leading laboratories pursuing research in the highest static magnetic fields technically feasible. Located in Grenoble, it is a French-German laboratory, jointly funded by the Max Planck Institut fur Festkorperforschung, in Stuttgart and the Centre National de la Recherche Scientifique. Five years ago, the laboratory has undertaken the development of 20 MW magnets. Two of them are now in operation and yield steady magnetic fields up to 30 T. The facility delivers around 5000 h of magnet time every year. (C) 2004 Elsevier B.V. All rights reserved