Bi2Te3-CoFe2O4 nanocomposite: Role of magnetic filler on thermoelectric properties

Abstract

The effect of magnetic CoFe2O4 (CFO) nanofillers on the thermoelectric properties of the Bi2Te3-CFO nanocomposite is investigated, and their role in the enhancement of thermoelectric properties is demonstrated. In the presence of a small magnetic field (25 mT), the electrical conductivity is enhanced by 16% and, simultaneously, the Seebeck coefficient is enhanced by 23%. The presence of CFO nanoparticles in the matrix of Bi2Te3 in the nanocomposite produces an interpenetrating network of the magnetically induced orientation of the magnetic moment of CFO, which results in the substantial reduction in the interface barrier by suppressing scattering of charge carriers at the interfaces. The simultaneous enhancement in the electrical conductivity and Seebeck coefficient in the presence of the small magnetic field resulted in an ∼52% enhancement of figure of merit for the Bi2Te3-CFO (4 wt. %) nanocomposite.