Experimental Artifacts in MOKE Measurements Induced by Paramagnetic Sample Holders.

A. MUÑOZ-NOVAL; C. J. BONIN; F. BONETTO; M. GARCÍA

Sao Paulo, Brasil

Encuentro; Autumn Meeting 2022 of the Brazilian Physical Society; 2022

Sociedade Brasileira de Fisica

We describe here an artifact that may affect tomagneto-optical Kerr (MOKE) measurements. When paramagnetic sample holders withnon-negligible susceptibilities are used, the inhomogeneity of the appliedmagnetic field can induce forces and torques on it, shifting the reflectedbeam, and altering its intensity at the photodetector. The effect is spatially evenand can be avoided using low susceptibility paramagnetic or diamagnetic sampleholders. We also present a detailed analytical description of the magneticforces involved and provide some estimated values of the reflected beam shifting,showing that typical paramagnetic sample holders can effectively distort theMOKE signal. In addition, we show how the artifact can be removed from theexperimental curves with an appropriate data analysis in symmetrical hysteresisloops.