| Abstract
| - A high-temperature, controlled atmosphere Faraday magnetometer has been used to measure the magnetic susceptibility of La1−xSrxCoO3−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.
- High-temperature, controlled atmosphere magnetic measurements show that the magnetic susceptibility of La1−xSrxCoO3−δ (LSC) becomes independent of Co oxidation state and Sr doping above 800 °C, consistent with metallic valance electrons. However, the persistence of a large Curie-Weiss susceptibility, even at high temperatures, suggests the coexistence of more localized electronic configurations. One possible explanation is a locally inhomogeneous electronic structure consisting of intermediate-spin and high-spin subdomains.
|
