Seebeck coefficient of Ca1–xPrxMnO3–δ paramagnetic manganites


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

The Seebeck coefficient (S) of Ca1–xPrxMnO3–δ (х = 0, 0.05, 0.10, 0.15) manganites with a perovskite-like structure has been measured in air at temperatures (T) from 300 to 1200 K. The negative sign of their S indicates that all of the samples have n-type conductivity. The observed increase in the magnitude of the Seebeck coefficient with increasing T is interpreted in terms of small-polaron transport with allowance for the decrease in Mn3+ concentration as a result of the disproportionation reaction 2Mn3+ = Mn2+ + Mn4+. Based on a theoretical analysis of experimental S(T) data, we calculated equilibrium constants for the disproportionation reaction, carrier concentration, and the concentration of sites available for carrier migration as functions of temperature. It has been shown that, for an adequate analysis of electron hopping and calculation of the Seebeck coefficient of the electron-doped manganites, the spin state of the Mn4+ ions should be taken into account.

About the authors

I. A. Leonidov

Institute of Solid State Chemistry, Ural Branch

Author for correspondence.
Email: leonidov@imp.uran.ru
Russian Federation, Pervomaiskaya ul. 91, Yekaterinburg, 620990

E. I. Konstantinova

Institute of Solid State Chemistry, Ural Branch

Email: leonidov@imp.uran.ru
Russian Federation, Pervomaiskaya ul. 91, Yekaterinburg, 620990

M. V. Patrakeev

Institute of Solid State Chemistry, Ural Branch

Email: leonidov@imp.uran.ru
Russian Federation, Pervomaiskaya ul. 91, Yekaterinburg, 620990

A. A. Markov

Institute of Solid State Chemistry, Ural Branch

Email: leonidov@imp.uran.ru
Russian Federation, Pervomaiskaya ul. 91, Yekaterinburg, 620990

V. L. Kozhevnikov

Institute of Solid State Chemistry, Ural Branch

Email: leonidov@imp.uran.ru
Russian Federation, Pervomaiskaya ul. 91, Yekaterinburg, 620990

Supplementary files

Supplementary Files
Action
1. JATS XML

Copyright (c) 2017 Pleiades Publishing, Ltd.