Measurement of Magnetic Hysteresis using X-ray Reflectivity
What is it about?
This research looks at the X-ray reflectivity during a hysteresis cycle from a thin magnetic permalloy (iron and nickel) film. By tuning to the iron L3 absoprtion edge the reflectivity becomes sensitive to the iron magnetisation. This was measured for different polarisations i.e. with the incident polarisation set to linear horizontal (sigma), linear vertical (pi), circular left and circular right.
Why is it important?
The results indicate that the profile of the reflectivity during a hysteresis cycle do not always resemble magnetisation due to a non-linear dependence on the magnetic moment of the ions. This depends strongly on both polarisation and energy. This is important since hysteresis curves measured with reflectivity (or any scattering technique) could look much more complicated than the underlying magnetisation. This study will help researchers to understand the profile of hysteresis curves measured with reflectivity and other X-ray scattering techniques which is important for measuring the underlying reversal processes with depth resolution and element specificity.