Physical/Magnetic Sample Characterization

Responsible: Dr. C. Strohm - FS-PS

Physical and Magnetic Sample Characterization

The DESY Nanolab offers access to a Cryogen Free Measurement System (CFMS) for the characterization of various physical properties over a wide range of temperature and field.

Superconducting Magnet

Filed range: ±14 T, 20 bit resolution

Homogeneity: 0.1 % over 1 cm x dia. 1 cm

Persistent mode decay rate 10 ppm/hour

Ultra low field option: 4 quadrant power supply for ± 30 mT, continuous sweeps across 0 T.

Sample Cryostat - Variable Temperature Insert

Temperature range: 2 K - 400 K

Cool-down time to 2K: approx. 60 min.

Vibrating Sample Magnetometer

Frequency: typically 20 Hz

Sample size: 5 mm or smaller

Noise and resolution: few x 10-6 emu

Cooling: sample in static He exchange gas

AC Susceptibility

Frequency: 1 Hz – 20 Hz

Maximum AC field 20 Gauss @ 100 Hz

Nominal sensitivity: 10-7 emu at 4 K

Sample size: 5 mm or smaller

Cooling: sample in static He exchange gas

AC and DC Resistivity and Hall Effect

Samples size: max 5 mm x 10 mm

DC current supply (Keithley 2400): 1 nA – 1 A

DC resistance measurement: 100 nW – 1 GW

Voltage sensitivity (Keithley 2182): 10 nV – 100 V

Frequency range AC: 1 mHz – 100 kHz

Current source range AC:  2 pA – 100 mA

Voltage measurement range AC: 10 nV – 1 V

Geometry: parallel and perpendicular to field

Cooling: sample in static He exchange gas

AC Calorimetry

Heat capacity resolution: 1 nJ/K at 2 K

Sample dimensions (typ.): 100 mm x 200 mm

Cooling: sample on membrane in static He exchange gas.

Thermal Transport

Thermocouple based thermal transport and thermoelectric effect measurements.

Needs significant preparation effort and change of sample cryostat configuration.

Cooling: sample in vacuum calorimeter placed in He flow of VTI.

Contact

Dr. C. Strohm - +49 (0)40 8998 2805
       cornelius.strohm@desy.de