SQUID Magnetometer

MPMS XL Magnetometer from Quantum Design (USA); 2012

The most sensitive magnetometer, in which changes of the magnetic flux are measured with the Superconducting Quantum Interference Device (SQUID); equipped with the auxiliary probes for investigating changes in magnetic properties induced by light or external pressure, as well as the electric conductivity probe for the magnetoresistance measurements. The instrument is filled with liquid helium from the transport dewar. Thanks to perfect sensitivity, weak magnets and very small smaples, including the nano-sized ones, may be investigated.

Technical details:

Temperature range 1.9 - 400 K (+ oven up to 800 K)
Temperature accuracy ±1 %
Magnetic field range ±7 T
Field setting resolution 0.5 G (to 5000 G), 2 G to 7 T
Field uniformity 0.01 % over 4 cm
Residual field < 5 G (Oscillation mode)
< 30 G (No-overshoot mode)
DC sensitivity < 10-8 emu = 10-11 J/T (to 2000 G)
< 6*10-7 emu (to 7 T)
Range of measurement ± 5 emu
AC susceptibility measurement 0.1 Hz - 1 kHz, sensitivity 10-8 emu
AC field amplitude 0.01 Oe - 3.9 Oe
Additional equipment Light fiber optic probe (UV-Vis)
High pressure cell probe
Electric conductivity measurement set-up

Application:

SQUID magnetometer is the most sensitive device for measuring magnetic properties of materials. It is used for research on molecular magnets, nanoparticles, metallic thin films for spintronics, intermetallic compounds, superconductors and multiferroics. Measurement possibilities:

  • Magnetization and magnetic susceptibility as a function of magnetic field HDC, temperature or time, as well as light- or pressure-induced changes in magnetic properties
  • AC magnetic susceptibility χAC = χ' - iχ'' as a function of temperature and of the frequence and the amplitude of the oscillating field, in zero- or non-zero constant magnetic field HDC
  • Electric conductivity as a function of temperature and magnetic field

Department in which the equipment is in use:

Department of Magnetic Research (NZ34), Department of Materials Science (NZ53)