Magneto-Luminescence Thermometry with Magnetic Circularly Polarized Luminescence

Lanthanide(III) materials display remarkable optical properties, making them valuable for advancing remote luminescent sensors. The narrow emission bands and energy-transfer processes can be tailored to respond to external stimuli, such as temperature changes and magnetic fields. The application of magnetic fields lifts the Zeeman degeneracy, creating electronic spin polarization, and giving rise to magneto-optical phenomena. Magnetic circularly polarized luminescence (MCPL) is a magneto-optical technique in which the differential emission of left and right circularly polarized light is induced by a magnetic field oriented parallel or antiparallel to the light propagation axis. In the context of lanthanide(III) materials, this technique has only been explored in a few studies as a characterization tool. In this study, we present MCPL for a Dy(III) complex for the first time, highlighting its significant potential for magneto-luminescence thermometry. By studying the [Dy(acac)₃(phen)] complex (phen: 1,10-Phenanthroline; acac: acetylacetonate) as an example, a maximum relative sensitivity of 19.7% K^-1 was observed at 293 K, highlighting the tremendous potential that MCPL emitters hold in the field of luminescent thermometers.