SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 43: Poster: Correlated Electrons II
TT 43.6: Poster
Mittwoch, 29. März 2023, 15:00–18:00, P2/OG3
Electrical and thermal transport properties of delafossite oxide CuCr1−xFexO2 — •Mithun Kumar Majee1, Ratnamala Chatterjee1, and Preeti Bhobe2 — 1Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India — 2Department of Physics, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore-453552, India
In order to improve the thermoelectric property of a material the effect of phonon/magnon drag, and spin fluctuations are other central parameters apart from carrier concentration, and lower thermal conductivity. It is known from the literature that CuCrO2 has a large Seebeck value of around 350 µV/K at room temperature, but its electronic concentration is low, hence the thermoelectric figure-of-merit (ZT) turns out to be quite poor. Hence to better its ZT, we attempt to replace some Cr ions with Fe in the series, CuCr1−xFexO2 (0<x<1) and study its electrical and thermal conductivity, heat capacity, and Seebeck coefficient. Our results exhibit a large and complex Seebeck coefficient in 20 K<T<380 K. The low-temperature electrical conduction is observed to obey 3D variable range hopping mechanism. Unlike, nonmagnetic Cu-based Delafossites, we show that the thermal conductivity is strongly affected by spin-phonon scattering in CuCr1−xFexO2 compositions. The heat capacity measurements identify the Debye temperature and effects due to magnetic ordering temperatures. Out of the different contributed processes, the role of the phonon drag effect and complexity in temperature dependence is observed in the Cr-rich compositions.