Improving magnetic nanothermometry accuracy through mixing-frequency excitation

TL;DR

This paper introduces a new phase measurement method under mixing-frequency excitation that enhances the accuracy of magnetic nanothermometry by reducing phase shift errors and improving signal-to-noise ratio, achieving sub-Kelvin temperature measurement errors.

Contribution

It proposes a novel temperature model and phase measurement technique based on mixing-frequency excitation for magnetic nanoparticle thermometry.

Findings

Achieves static temperature measurement error < 0.1K

Achieves dynamic temperature measurement error < 0.2K

Improves signal-to-noise ratio and reduces phase shift errors

Abstract

In this study, we proposed a temperature model of magnetic nanoparticle relaxation and a phase measurement method under a mixing-frequency excitation field, which can improve the temperature accuracy of magnetic nanothermometry. According to the Debye-based magnetization model for magnetic nanoparticles, the phases at the mixing frequencies are used to solve the relaxation phase delay to the magnetic field with the higher frequency. The method could improve the signal-to-noise ratio of the magnetic response signal, and also weaken the phase shift of the detection coils caused by temperature changes. Experimental results show that the method can achieve static temperature measurement error less than 0.1K and dynamic temperature measurement error less than 0.2K.