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YAlO 3 :Mn nanocrystals obtained in sol‐gel and their properties
Author(s) -
Talik E.,
Baran M.,
Skrzypek D.,
Szubka M.,
Guzik A.,
Pajączkowska A.
Publication year - 2010
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201000310
Subject(s) - manganese , electron paramagnetic resonance , yttrium , nanocrystalline material , analytical chemistry (journal) , x ray photoelectron spectroscopy , materials science , impurity , valence (chemistry) , perovskite (structure) , single crystal , scanning electron microscope , chemistry , crystallography , nuclear magnetic resonance , metallurgy , physics , organic chemistry , chromatography , composite material , oxide
Manganese‐doped yttrium aluminum perovskite (YAP) nanocrystalline samples of 0.05 at%, 0.2 at% and the reference single crystal of predicted 0.02 at% Mn, 0.02% Si concentration in YAP were investigated by the following methods: X‐ray powder diffraction, scanning electron microscopy, EPR, SQUID and XPS. These examinations revealed that the obtained material was not single phase and the trace of Y 3 Al 5 O 12 (YAG) appeared. As is evident from EPR studies, the manganese in all investigated samples is occupying an yttrium site and the valence of manganese remains as Mn 2+ . The EPR spectra of both powder YAP:Mn samples are the same, an expected difference in the intensity well reflects the nominal concentration of manganese. The single crystal perovskite YAlO 3 doped with manganese showed very complex and strongly anisotropic EPR spectrum. The EPR data showed the presence of Mn 2+ ions substituting yttrium site and Cr 3+ and Fe 3+ undesirable impurities which occupied aluminum site. The magnetic moments of manganese calculated for the nanopowders confirmed Mn 2+ state. The SEM/EDS and XPS analyses showed the chemical composition of nanopowders as very consistent for both methods. For both samples the lower content of aluminum in relation to the nominal value was found. The SEM images show that the sample 0.2 at% Mn has more agglomerated structure. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)