Xiaoning Sun

Thermoelectric properties of CNTs/Mn0.7Zn0.3Fe2O4 composite fabricated by spark plasma sintering

As a new kind of environment-friendly material, thermoelectric material has got more and more attention and rapid development. In this work, the CNTs/Mn0.7Zn0.3Fe2O4 composite was fabricated by spark plasma sintering (SPS) technique, and the influence of SPS temperature on the thermoelectric properties was discussed. The average grain sizes increased from 50 to 400 nm with increasing SPS temperature from 600 °C to 800 °C. The electrical conductivity of CNTs/Mn0.7Zn0.3Fe2O4 composite demonstrated a typical semiconducting-like behavior, and the value can reach about 77 s m−1, which increased by 4–8 orders of magnitude in comparison with that of traditional Mn–Zn ferrites. The Seebeck coefficient was negative suggesting a n-type conduction, and its value was about −128 ~ −213 μV K−1. By optimizing the sintering temperature, the power factor is significantly improved and the thermal conductivity is reduced simultaneously, which results in a ZT value of about 0.083. These results demonstrate that the CNTs/Mn0.7Zn0.3Fe2O4 composite is a potential thermoelectric material.