High Temperature Magnetic Properties of Sr-Doped Lanthanum Cobalt Oxide (La1−xSrxCoO3−δ)

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• 作者：Dinesh Baskar ; Stuart B. Adler
• 刊名：Chemistry of Materials
• 出版年：2008
• 出版时间：April 22, 2008
• 年：2008
• 卷：20
• 期：8
• 页码：2624 - 2628
• 全文大小：399K
• 年卷期：v.20,no.8(April 22, 2008)
• ISSN：1520-5002

文摘

A high-temperature, controlled atmosphere Faraday magnetometer has been used to measure the magnetic susceptibility of La_1−xSr_xCoO_3−δ (LSC) as a function of temperature, Sr content (x), and oxygen nonstoichiometry (δ). Above 800 °C the magnetic susceptibility becomes independent of Co oxidation state and Sr doping, consistent with metallic valance electrons. Under these conditions, conductivity measurements as a function of x, T, and δ exhibit classic metallic behavior, with resistivity scaling linearly with temperature and nonlinearly with defect concentration. However, a large Curie–Weiss susceptibility persists even at high temperatures, suggesting the coexistence of more localized electron configurations. We discuss this behavior in terms of existing theories of electronic and magnetic structure.