ICT2014 Abstracts

Magnetite, Fe₃O₄, has long been of interest to researchers due to the unique natures of charge ordering, ferrimagnetism, and magnetoresistance.[1-3] Recently, Viskadourakis et.al. observed high thermoelectric power factor in Fe₃O₄ on p-Si(100), which was explained by the accumulation of majority holes at the interface between SiO₂ and p-Si substrate due to the difference in their work functions.[4] It was analyzed by the relation of the energy band diagram of Fe₃O₄/SiO₂/p-Si heterostructure. The thermoelectric power factor defined as S²σ, where S is Seebeck coefficient, which depends on the density and the mobility of the carrier, and σ is electrical conductivity. In order to confirm the thermoelectric transport property, we have grown Fe₃O₄ thin-films on n-type, p-type, and semi-insulating Si(100) substrates using molecular beam epitaxy and have carried out the measurements of electrical resistivity and Seebeck coefficient as a function of temperature. In Fe₃O₄ thin films on n-type, p-type, and semi-insulating substrates, we obtained three different types in temperature-dependent resistivity behaviors. And we observed the diffusion of Si atoms from Si substrate to the film through HRTEM. In this presentation, we will discuss about the thermoelectric transport property of Fe₃O₄on Si(100) substrates.

[1] E. J. W. Verwey, Nature 144, 327 (1939)

[2] V. V. Gridin et al., Phys. Rev. B 53, 15 528 (1996)

[3] H. Matsuda et al., J. Appl. Phys. 98, 063903 (2005)

[4] Z. Viskadourakis et al., Appl. Phys. Lett. 101, 033505 (2012)