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High Temperature Transport Property of Copper site Doped La 2 CuO 4
Author(s) -
Xu Wei,
Liu Yong,
Chen Dongliang,
Lin YuanHua,
Wu Zhonghua,
Xie Yaning,
Zhang BoPing,
Cheng Bo,
Nan CeWen,
Wu Ziyu
Publication year - 2011
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.04259.x
Subject(s) - copper , doping , materials science , metallurgy , optoelectronics
The transport properties of p ‐type polycrystalline La 2 Cu 1− x M x O 4 (MCo and Mn) have been investigated in the high temperature domain above room temperature up to 973 K. The electrical resistivity of La 2 Cu 1− x M x O 4 undergoes a temperature driven semiconducting (insulating) to metallic transition at high temperature (∼750 K) and a doping induced metal to semiconductor transition at room temperature. The Arrhenius plot of the ln(ρ/ T )∼1/ T shows a conducting mechanism and in the La 2 Cu 1− x M x O 4 (M:Co and Mn) a transition temperature was found at around 750 K similar to what was observed in the La 2− x RE x CuO 4 (RE: Pr, Nd and Y) system. We therefore suggest that in these doped ceramics the metal–insulator (semiconductor) transition at ∼750 K should be attributed to combined effects of a strong phonon scattering mechanism due to thermal activation, oxygen vacancies and structural disorders. Furthermore, a site‐dependent influence of electrical resistivity in La 2 CuO 4 ‐based ceramics was distinguished by combining thermoelectric measurements and X‐ray absorption spectroscopy. The doping induced transition is then associated with large imperfections present in the CuO 2 layer, consistent with a dominant role of the single CuO 2 layer in the charge transport mechanism of La 2 CuO 4 ‐based materials.