Nanoscale Materials Science  
Forces, surfaces and magnetism
Molecular surface science
Nanostructured coatings
Magnetic thin films and devices

Room Temperature Magnetic Force Microscope (RT-MFM)

The RT-MFM is a custom made microscope used for rapid sample and/or cantilever testing. It operates in near high vacuum which increases sensitivity by a factor of 30 compared to ambient air. Routinely, a lateral magnetic resolution of 15 nm is achieved in non-contact operation mode. The detection system consists of a fiber interferometer system, a software PLL running on a real time hardware system from NI and an intuitive data acquisition program. Typically, the frequency shift (detuning of the cantilever resonance frequency in the force field of the sample) is recorded, but also oscillation phase and amplitude and/or cantilever oscillation dissipation can be recorded. Additionally, the sensor-sample distance can be measured precisely in order to facilitate a later quantitative analysis of the MFM images.

Fig. 1: Front view of the RT-MFM including the electronics rack [preliminary image].
Room Temperature Atomic Force Microscope (RT-AFM)

The RT-AFM is a Digital Instrument Nanoscope I which can perform AFM scans in contact mode. It operates in air and allows for rapid sample/cantilever exchange. Routinely, a lateral resolution of about 40-50 nm is achieved. The detection system consists of a beam deflection system with DI electronics recording the traveled vertical piezo height or cantilever deflection.

Fig. 2: Front view of the RT-MFM including the electronics rack.
Physical Properties Measurement System (PPMS)

The PPMS is a cryostat based measurement system from Quantum Design. It features a LHe/LN2 cryostat including a 7T superconducting magnet. The temperature of the sample can be varied continuously from 1.9K to 400K. All measurement modes are fully automated and allow for extended batch measurements.

The insert of the cryostat is exchangeable and allows the following measurement techniques:

  • vibrating sample magnetometer (full hysteresis curve, coercive field, saturation field, saturation magnetization, remanent magnetization, subset curves).

  • torque magnetometer (AC/DC magnetization, anisotropy).

  • thermal / electrical transport system (AC/DC electrical resistivity, thermal conductivity, Seebeck coefficient, figure of merit.

Fig. 3: The upper left image shows the complete PPMS system, the right upper image shows the insert of the cryostat. Left down, the sample pucks for the electrical conductivity and VSM are as well as the torque magnetometer sample holder are depicted. 
zurück  Links  Druckansicht