The effect of Cu-sites doping on electrical properties of La2CuO4 as thermoelectric material

Abstract

The electrical conductivity and thermoelectric power for solid solutions of La2Cu0.gM0.104 (M = Mn, Fe, Co and Ni) prepared by polymeric precursor synthesis were measured between 300 and 1173 K to test its suitability as a thermoelectric material. Fe-, Mn-and Ni-doped compositions exhibited a metal-semiconductor transition with decreasing temperature, whereas Co doping showed a semiconducting behaviour in the entire temperature range of measurement. With Cu-sites doping in La2CuO4, power factors were not enhanced.

Investigation of the thermoelectric properties of La2CuO4 ceramics with the addition of Ag

“…YBa 2 Cu 3 O 7À δ , to best of our knowledge, has the highest reported ZT value (0.6 at 300 K) of the high-temperature Cu-based superconductors [18], although this result requires further verification [19]. La 2 CuO 4 has a large Seebeck coefficient of 340 μV/K at room temperature [15,17], and several groups have investigated the TE properties of La 2 CuO 4 doped with various elements [20][21][22]. Most of those reports have focused on the high temperature TE properties of these materials.…”

High Temperature Transport Property of Copper site Doped La2CuO4

“…Besides the oxygen vacancy contribution, the doping stoichiometry, especially that of the doping site, may significantly contribute to the electrical resistivity. Seok et al 17 observed a doping‐induced decrease of the electrical conductivity in 1 at.% transition metal (Fe/Mn/Ni/Co) doped La 2 CuO 4 . This work also reported an interesting fact that the temperature dependence of the electrical conductivity experiences a metal‐semiconductor transition for Fe‐, Mn‐, and Ni‐doped La 2 Cu 0.9 M 0.1 O 4 , 17 while no transition occurs in Co‐doped species 17 .…”

“…Seok et al 17 observed a doping‐induced decrease of the electrical conductivity in 1 at.% transition metal (Fe/Mn/Ni/Co) doped La 2 CuO 4 . This work also reported an interesting fact that the temperature dependence of the electrical conductivity experiences a metal‐semiconductor transition for Fe‐, Mn‐, and Ni‐doped La 2 Cu 0.9 M 0.1 O 4 , 17 while no transition occurs in Co‐doped species 17 . Seok et al 17 attributed the distinction to the low spin configuration of Co 3+ , in comparison with high spin states for other metals.…”

“…Seok et al 18 then studied the Co‐doped La 2 Cu 1− x Co x O 4 at different doping levels and indicated that the transition occur only in highly doped samples ( x >0.05) due to the charge localization and hole doping. Doping the lanthanum site in La 2 CuO 4 ‐induced superconductivity 16 at low temperatures while the copper‐site‐doped systems showed doping‐induced decrease of electrical conductivity at room temperature, 17 it implies that the low‐ and high‐temperature transport behavior of La 2 CuO 4 ‐based systems are strongly dependent upon the atomic doping site and the concentration of dopants.…”

“…The temperature‐dependence of electrical resistivity of Co‐doped La 2 CuO 4 are complicated since the metal‐to‐semiconductor transition can either exist 17 or disappear 18 in highly doped samples ( x >0.05). To clarify and understand the doping‐induced‐structure‐property relationship and the property behavior upon temperature, an integral investigation is necessary.…”