Electronic conduction in La-based perovskite-type oxides |
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Authors: | Hisashi Kozuka Kazushige Ohbayashi Kunihito Koumoto |
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Affiliation: | 1.NGK Spark Plug Co., Ltd, 2808, Iwasaki, Komaki-shi, Aichi 485-8510, Japan;2.Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho Chikusa-ku, Nagoya 464-8603, Japan |
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Abstract: | A systematic study of La-based perovskite-type oxides from the viewpoint of their electronic conduction properties was performed. LaCo0.5Ni0.5O3±δ was found to be a promising candidate as a replacement for standard metals used in oxide electrodes and wiring that are operated at temperatures up to 1173 K in air because of its high electrical conductivity and stability at high temperatures. LaCo0.5Ni0.5O3±δ exhibits a high conductivity of 1.9 × 103 S cm−1 at room temperature (R.T.) because of a high carrier concentration n of 2.2 × 1022 cm−3 and a small effective mass m∗ of 0.10 me. Notably, LaCo0.5Ni0.5O3±δ exhibits this high electrical conductivity from R.T. to 1173 K, and little change in the oxygen content occurs under these conditions. LaCo0.5Ni0.5O3±δ is the most suitable for the fabrication of oxide electrodes and wiring, though La1−xSrxCoO3±δ and La1−xSrxMnO3±δ also exhibit high electronic conductivity at R.T., with maximum electrical conductivities of 4.4 × 103 S cm−1 for La0.5Sr0.5CoO3±δ and 1.5 × 103 S cm−1 for La0.6Sr0.4MnO3±δ because oxygen release occurs in La1−xSrxCoO3±δ as elevating temperature and the electrical conductivity of La0.6Sr0.4MnO3±δ slightly decreases at temperatures above 400 K. |
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Keywords: | electronic conduction electrical conductivity carrier concentration carrier mobility effective mass relaxation time |
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