Sensing of temperature through magnetooptical domain wall susceptibility

Abstract

Temperature measurements are vital in laboratory and industry settings. We demonstrate magnetooptical measurement schemes to relate magnetic and micromagnetic features to temperature sensing using magnetooptical active iron garnet films. A particular focus is on a temperature measurement scheme based on changes in the magnetic domain wall susceptibility, analyzing the resulting magnetooptical signal amplitude in a magnetic modulation field. The range of application is limited by the Néel temperature of the sensing garnet material. Temperatures are perceived with an accuracy of below 0.1 °C from the changes in the magnetooptical domain wall response. The thin film sensor element features additionally high sensitivity magnetic field and electrical current sensing capabilities, allowing for multi-functional sensor applications.