Facilities

FTIR and Kerr spectroscopy
 

Equipment for FTIR- and Kerr-spectroscopy with accessories for photoluminescence and magneto-optic measurements from the visible to the far-infrared spectral range. Cryogenic instrumentation allows investigations down to 2.2 K at moderate magnetic fields up to +/-1 kG.
 
The Bruker EQUINOX-55 is equipped with the step scan option for performing (thermo , electro-, photo-, piezo-) modulated transmission and reflection studies.


SQUID Magnetometer

Superconducting QUantum Intereference Device (-SQUID) magnetometry is the currently most sensitive method to quantify traces of magnetic substances like thin magnetic films, nanoscale magnets and precipitates. In material science the integral magnetic moment of tiny samples (max. 3 x 3 x 9 mm) in dependence of a magnetic field at fixed temperature (Hysteresograph), or its temperature dependence at fixed magnetic field (Susceptometer) is measured. Beside the ac-susceptibility- and ultra-low-field-options a fibre optic accessory is available to perform light- and thermal-wave-modulated magnetization experiments.
 
Technical specifications:
Type / Model: MPMS-XL-7
Manufacturer: Quantum Design, USA
Magnetic field: +/- 7 Tesla in 2 G steps
Temperature: 1,9-350 K, 0.1K steps
Magnetic moment resolution: 5*10-9 emu

Laser optoacoustics

Bulk waves and surface acoustic waves (SAW) are generated by illuminating samples with laser pulses of about 10 ns duration. Rapid heating generates mechanical stress that propagates in the bulk and, in the case of solids, also on the surface of the sample. For measurements of the waves we use standard piezoelectric techniques and various kinds of optical methods based on interferometry, beam deflection (knife edge technique), and optical reflectance.
 
Equipment:
Q-switched Nd:YAG lasers with various frequency conversion options: Second, third harmonic generation and OPO (optical parametric oscillator) pumping.