Magnetics Laboratory

The basic activities of the Magnetism Laboratory are the calibration of magnetic field measurement devices and characterization of magnetic materials. The laboratory establishes national standards in these areas, maintains their operational condition and transfers the traceability to secondary labs.

Magnetic field measurements with our primary standard, NMR Teslameter, are performed in the range of of 0.35 T - 3.4 T with an expanded uncertainty of 7 ppm.

Calibration of magnetic field measurement devices in the range of 0 mT - 10 mT is performed in a Helmholtz coil and in the range of 10 mT - 180 mT using a spilt-field coil. To generate DC magnetic fields and perform calibrations up to 2 T, an electromagnet is used. Calibration services are offered with an uncertainty of 0.3% for 0 mT - 10 mT DC and 0 mT - 5 mT AC ranges, 0.35% - 0.5% for the 10 mT - 180 mT DC range and 0.2% for the 180 mT - 2000 mT DC range.

Measurements of magnetic flux are performed in the range of 10-6-1 Wb with an uncertainty of 0.09%.

Calibration of magnetic field coils in the range of coil constants of 30 mT/A - 50 mT/A is performed with an uncertainty of 0.2% for DC magnetic field in the range of 0 T - 1 T and 0.26% for AC magnetic field in the range of 0 mT - 5 mT.

Characterization of magnetic materials is done using a VSM (Vibrating Sample Magnetometer) and SQUID (Superconducting Quantum Interference Magnetometer) magnetometers. Basic parameters of magnetic materials, such as magnetic permeability (m), saturation magnetization (MS), coercive field (HC), remanent magnetization (Mr) are determined using these devices. VSM and SQUID magnetometers are calibrated using materials like nickel and palladium whose specific magnetization is known and is traceable to international primary standards, which is confirmed by certificates. The SQUID magnetometer can perform measurements with an uncertainty of 0.1% at temperatures between 1.9 K and 400 K for magnetic fields in the range of 0 T - 5 T and magnetic moments in the range of 0.000125 emu - 1.25 emu.

Additionally, the Magnetism Laboratory is equipped with a Magnetooptic Visualization System for direct observation of magnetic field spatial distribution on the surface of magnetic materials. The principle of operation of this system is based on the Faraday effect, i.e. the rotation of the polarization direction of polarized light passing through a magnetic field. To achieve Faraday rotation, special transparent magnetic Yttrium Iron Garnet films with the in-plane direction of magnetization are used. Measurements of local magnetic field are performed in the range of 0.1 mT - 100 mT with a spatial resolution of 1 mm and uncertainty of 4%.