Open AccessThe origin of EPIR effect in Nd0.7Sr0.3MnO3 ceramics
Author(s) -
Changping Yang,
Shun-Sheng Chen,
Dai Qi,
Xiaoguo Song
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.117202
Subject(s) - materials science , grain boundary , ceramic , crystallite , space charge , condensed matter physics , electrode , phase boundary , nonlinear system , composite material , phase (matter) , microstructure , metallurgy , electron , chemistry , physics , organic chemistry , quantum mechanics
Polycrystalline ceramic Nd0.7Sr0.3MnO3 is synthesized using high-energy ball milling and post heat treatment method. The properties of electric transport are measured using direct current (DC) 4-wire and 2-wire methods. The results show that both the grain (phase) boundary and the electrode-bulk contact interface has interfacial resistance and space charge layer. The two kinds of space charge regions have greatly different effects on the DC transport: for the former, the I-V curve exhibits nonlinear characteristic and no EPIR effect takes place; for the later, however, an obvious EPIR effect is observed even if the I-V curve also shows nonlinear behaviour. It well suggests that for the ceramic Nd0.7Sr0.3MnO3, only the electrode-bulk contact interface can induce the EPIR effect although there is a similar nonlinear I-V characteristic for the grain (phase) boundary and the electrode-bulk contact interface.