A material has, depending on the composition, different magnetic properties. When light is shone upon a magnetized surface, the changes to the reflected light can be described with the magneto-optic Kerr effect (MOKE). This is very useful to investigate the magnetization structure of materials. In this research we looked at four samples with different concentrations of Gd1-x-yTbyFex.
We used for this experiment the polar MOKE in which the constructed magnetic field is perpendicular on the sample. By looking at different temperatures we can see when nucleation occurs, after which the magnetization declined. By looking at different samples with different concentrations, we could conclude that the concentrations of iron had a larger influence on the magnetic properties than the concentrations of terbium.
5 mW OEM diode laser, with a wavelenght of 677 nm.
Two adjustable mirrors for aiming the laser.
Linear polarisator, to polarize the coming bundle horizontally.
Semi-transparent mirror for sending the reflecting bundle.
Linear polarisator, to polarize the coming bundle vertically.
Detector, Melles Griot.
Electromagnet with a maximum of 0.39 Tesla, with a power source.
Knob for turning in the lenght of the sample (X).
Knob for turning in the width of the sample (Y).
Knob for turning in the height of the sample (Z).
Knob for turning in the angle of the sample (θ).
Vacuum pump (not visible on the photo).
Neocera LTC-21 temperature controller (not visible on the photo).