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Cationic disorder and Mn3+/Mn4+ charge ordering in the B′ and B″ sites of Ca3Mn2NbO9 perovskite: a comparison with Ca3Mn2WO9
- Source :
- Digital.CSIC. Repositorio Institucional del CSIC, instname
- Publication Year :
- 2013
- Publisher :
- Elsevier, 2013.
-
Abstract
- We describe the preparation, crystal structure determination, magnetic and transport properties of two novel Mn-containing perovskites, with a different electronic configuration for Mn atoms located in B site. Ca3Mn 3+ 2WO9 and Ca3Mn 3+/4+ 2NbO9 were synthesized by standard ceramic procedures; the crystallographic structure was studied from X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD). Both phases exhibit a monoclinic symmetry (S.G.: P21/n); Ca3Mn 2WO9 presents a long-range ordering over the B sites, whereas Ca3Mn2NbO9 is strongly disordered. By >in-situ> NPD, the temperature evolution of the structure study presents an interesting evolution in the octahedral size (〈 Mn-OâŒ) for Ca3Mn2NbO9, driven by a charge ordering effect between Mn3+ and Mn4+ atoms, related to the anomaly observed in the transport measurements at T≈160 K. Both materials present a magnetic order below TC=30 K and 40 K for W and Nb materials, respectively. The magneto-transport measurements display non-negligible magnetoresistance properties in the paramagnetic regime.© 2013 Published by Elsevier Inc. All rights reserved.<br />C.A.L. and M.E.S. thanks a CONICET fellowship. J.C.P. thanks CONICET (Project PIP 2008-01360), SECyT-UNSL (Project 7707 and Project 2-1612). R.D.S. acknowledges financial support of ANPCYT (Project PICT 2011-0752) and SEPCyT-UNCu (06/C389). J.C.P. and R.D.S are member of CONICET. J.A.A. acknowledges the financial support of the Spanish Ministry of Education to the project MAT2010-16404.
- Subjects :
- Materials science
Charge ordering
Magnetoresistance
Crystal structure
Ciencias Químicas
Double perovskite
Condensed Matter Physics
Química Inorgánica y Nuclear
Electronic, Optical and Magnetic Materials
Inorganic Chemistry
Crystallography
Paramagnetism
Octahedron
Crystal structures
Transport properties
Materials Chemistry
Ceramics and Composites
Physical and Theoretical Chemistry
Powder diffraction
CIENCIAS NATURALES Y EXACTAS
Magnetic behaviour
Natural bond orbital
Perovskite (structure)
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- Digital.CSIC. Repositorio Institucional del CSIC, instname
- Accession number :
- edsair.doi.dedup.....a1456578cea2ac39d75f3bca4f95796f