Laboratory of magnetooptics

Measuring method:

intensity differential magneto-optical method based on vector magnetometry, investigation of linear and quadratic magneto-optical effects.

Laboratory equipment:

red laser diode (670 nm), blue laser (405 nm), infrared laser (1550 nm), photo-elastic modulator (PEM), polarizers, Wollaston prism, quarter wave-plate Si detectors, Lock-in amplifier, power supply Kepco, antivibration table, Teslameter, DAQ convertors, air coils and coils with poles extensions, sample holder with possibility of rotation and movements in xyz axes, holder for sample loading.

Investigated materials:

solid ferromagnetic and ferrimagnetic materials – thin films, multilayers, amorphous and nanocrystalline materials based on Fe, Co and Ni.

Investigated quantities of materials:

• surface hysteresis loops (light penetration depth at metals is only a few tens of nanometers) and their parameters (coercive and anisotropy field, saturation and remanence of magneto-optical effects, dependence on the incident angle and light wavelength)
• vector magnetometry – sensitivity to the components of magnetization vector lying in the sample plane (longitudinal component – parallel with the plane of light incidence and applied magnetic field, transversal component – perpendicular to the plane of light incidence and applied magnetic field) and to the component perpendicular to the sample surface (polar component)
• analysis of magnetic anisotropy due to rotation of the sample and magnetic field
• monitoring the homogeneity of magnetic properties due to possibility of focusing laser beam into the different places on the sample surface
• investigation of depth and material sensitivity of magneto-optical effects
• modelling of magneto-optical response of thin-film systems (determination of refractive indexes and film thicknesses) using the models for light propagation in thin anisotropic films

Laboratory of magnetooptics