Relationship between angles for Mn-O-Mn and electrical properties of orthorhombic perovskite-type (Ca1-xSrx)MnO3

摘要

Orthorhombic perovskite-type (Ca1-xSrx)MnO3 (0 less than or equal to x less than or equal to 0.5) was synthesized by a standard ceramic technique. The cell constants increase monotonously with increasing x. The Rietveld analysis indicates that the Mn-O(1 and 2) distances are independent of x, whereas the Mn-O(1 and 2)-Mn angles increase with increasing x. Measurements of the electrical resistivity (rho) and the Seebeck coefficient (alpha) indicate that (Ca1-xSrx)MnO3 is an n-type semiconductor in the range 0 less than or equal to x less than or equal to 0.5. Both the logarithm of the electrical resistivity (log rho) and the activation energy (E-a) increase while the mobility (mu) decreases with increasing x. From these results, it is considered that the Mn-O(1 and 2)-Mn angles play an important role in the electrical properties. (C) 1998 Academic Press. [References: 15]