Novel Thermoelectric Cooling of Magnetic Sensors

Abstract

In situ thermoelectric cooling of GMR nanowires is a novel method to obtain reliable and more sensitive GMR devices. Bismuth telluride (BixTey) caps were used to provide localized thermoelectric cooling of GMR nanowires. BixTey nanowires were electrodeposited from aqueous acidic solutions containing different Bi3+ and HTeO2+ concentrations. GMR layered structures were electrodeposited from a Co-rich electrolyte using a pulsed potential technique. The highest Seebeck coefficients of -318.7 µV/K and 117 µV/K were measured for n-type and p-type nanowires, respectively. P-type nanowires were obtained for low Te concentrations (<30%). Initial experiments were conducted to study the effect of thermoelectric cooling on sensitivity of GMR nanowires. Results showed that using BixTey caps can improve magnetic sensitivity of GMR nanowires.