La0.7Sr0.3MnO3 toroidal inductor for low magnetic field sensing

Abstract

La0.7Sr0.3MnO3 (LSMO) toroidal inductors sintered at 1300°C for various sintering time have been fabricated for magnetic field sensing. The complex permeability spectra show relaxation character due to domain wall displacement. As the sintering time increases, the permeability increases and the resonance frequency fr decreases. Under applied magnetic field, the permeability decreases and fr increases. Large shift of fr by low fields was observed. The 8 hr sintering sample exhibits a best magnetic field to frequency transfer ratio of 5.13 kHz/G. Our measured results indicate that LSMO is a promising material for the design and fabrication of low-cost magnetic field sensors.