Manganite charge and orbitally ordered and disordered states probed by Fe substitution into Mn site in LnBaMn{sub 1.96}Fe{sub 0.04}O{sub 5}, LnBaMn{sub 1.96}Fe{sub 0.04}O{sub 6} and LnBaMn{sub 1.96}Fe{sub 0.04}O{sub 5.5} (Ln=Y, Gd, Sm, Nd, Pr, La)

Journal Article · Sat Aug 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.05.029· OSTI ID:21370535

Ueda, Yutaka ^[1]; Nomura, Kiyoshi ^[2]

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1. Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)
2. School of Engineering, The University of Tokyo, Hongo 7-3-1, 113-8656 (Japan)

The layered manganese oxides LnBaMn{sub 1.96}Fe{sub 0.04}O{sub y} (Ln=Y, Gd, Sm, Nd, Pr, La) have been synthesized for y=5,5.5 and 6. In the oxygen-saturated state (y=6) they exhibit the charge and orbital order at ambient temperature for Ln=Y, Gd, Sm, but unordered e{sub g}-electronic system for Ln=La, Pr, Nd. Fourfold increase of quadrupole splitting was observed owing to the charge and orbital ordering. This is in agreement with the jumplike increase in distortion of the reduced perovskite-like cell for the charge and orbitally ordered manganites compared to the unordered ones. Substitution of 2% of Mn by Fe suppresses the temperatures of structural and magnetic transitions by 20-50 K. Parameters of the crystal lattices and the room-temperature Moessbauer spectra were studied on 40 samples whose structures were refined within five symmetry groups: P4/mmm, P4/nmm, Pm-3m, Icma and P2/m. Overwhelming majority of the Fe species are undifferentiated in the Moessbauer spectra for most of the samples. Such the single-component spectra in the two-site structures are explained by the preference of Fe towards the site of Mn(III) and by the segmentation of the charge and orbitally ordered domains. - Moessbauer spectra were studied in manganites whose structures were refined with symmetry groups: P4/mmm, P4/nmm, Pm3m, Icma and P2.

• OSTI ID: 21370535
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 8; Other Information: DOI: 10.1016/j.jssc.2009.05.029; PII: S0022-4596(09)00236-9; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMBIENT TEMPERATURE
BARIUM COMPOUNDS
CUBIC LATTICES
GADOLINIUM COMPOUNDS
IRON COMPOUNDS
MANGANESE OXIDES
MOESSBAUER EFFECT
NEODYMIUM COMPOUNDS
PEROVSKITE
PRASEODYMIUM COMPOUNDS
SAMARIUM COMPOUNDS
SYMMETRY GROUPS
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0273-0400 K
TETRAGONAL LATTICES
YTTRIUM COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
MANGANESE COMPOUNDS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITES
RARE EARTH COMPOUNDS
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS