SQUID magnetometer for bulk and film samples

• Subject Area: Condensed Matter Physics
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564886575

The four working groups in the II. Physikalisches Institut mostly involved in the use of SQUID magnetometry synthesize solid state samples in polycrystalline, single-crystalline or film forms. Measure-ments of the magnetic susceptibility and magnetization are first required to precisely charac-terize samples and in particular to confirm phase purity. Comprehensive magnetometry stud-ies then not only deliver the magnetization as function of field or temperature but also yield evidence for phase transitions driven by field, temperature or another triggering entity. For the search of impurity phases as well as for identifying subtle anomalies in the magnetization a high precision is required. Within the II. Physikalisches Institut the interest in magnetometry is widespread including studies of quantum magnets and quantum criticality, skyrmion sys-tems, magnetic frustration, magnetoelectrics and multiferroics, itinerant and/or topological magnetism and unconventional superconductivity and its interplay with magnetic correla-tions. Sometimes an electric field or a current is required to control the material. Only a SQUID magnetometer can meet the resulting conditions in flexibility and precision.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: SQUID Magnetometer für Volumen- und Filmproben
• Instrumentation Group: 0150 Geräte zur Messung der magnetischen Materialeigenschaften
• Applicant Institution: Universität zu Köln
• Leader: Professor Dr. Markus Braden