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Multi‐frequency EPR studyof Cr 3+ doped lead titanate (PbTiO 3 ) nanopowders
Author(s) -
Erdem Emre,
Böttcher Rolf,
Semmelhack HansChristoph,
Gläsel HansJürgen,
Hartmann Eberhard
Publication year - 2003
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200309013
Subject(s) - electron paramagnetic resonance , octahedron , doping , particle size , materials science , superposition principle , lead titanate , lattice (music) , ceramic , mineralogy , condensed matter physics , analytical chemistry (journal) , nuclear magnetic resonance , crystallography , chemistry , crystal structure , physics , ferroelectricity , metallurgy , chromatography , optoelectronics , quantum mechanics , acoustics , dielectric
In our multi‐frequency EPR study of Cr 3+ doped PbTiO 3 nanopowder samples with varying mean particle size, three paramagnetic Cr 3+ centres (C1, C2, C3) with different axial fine structure (FS) parameters are identified, with one of them (C1) being compatible with former literature measurements on bulk and ceramics samples carried out in the X band. The superposition model by Newman and Urban was applied to translate the FS data into local displacements inside the distorted oxygen octahedra of the PbTiO 3 lattice. When going to nanopowder samples with mean particle size below a critical value, other than the centre C1 are no longer detectable. Instead, a new one (C4) appears, testifying a pronounced size effect. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)