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Title: Oxygen stoichiometry: A key parameter to tune structural phase diagram of La{sub 0.2}Sr{sub 0.8}MnO{sub 3-δ}

Low temperature x-ray powder diffraction studies, in conjunction with transmission electron microscopy on stoichiometric (δ = 0.01) and oxygen deficient (δ =0.12) samples of La{sub 0.2}Sr{sub 0.8}MnO{sub 3-δ} manganites have been carried out. These studies revealed that oxygen stoichiometry plays a key role in controlling ground state of electron doped manganites. It is observed that the La{sub 0.2}Sr{sub 0.8}MnO{sub 2.99} undergoes a first order phase transition from cubic (Pm-3m) to JT-distorted twin tetragonal (I4/mcm) phase associated with C-type antiferromagnetic ordering at ∼260K. This JT-distortion induced cubic to tetragonal phase transition get totally suppressed in La{sub 0.2}Sr{sub 0.8}MnO{sub 2.88}. The basic perovskite lattice of the off-stoichiometric La{sub 0.2}Sr{sub 0.8}MnO{sub 2.88} remains cubic down to 80K but undergoes a well-developed charge-ordering transition with 9x9 modulations at ∼260K.
Authors:
;  [1]
  1. UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore (M.P)-452001 (India)
Publication Date:
OSTI Identifier:
22490182
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1665; Journal Issue: 1; Conference: 59. DAE solid state physics symposium 2014, Tamilnadu (India), 16-20 Dec 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIFERROMAGNETISM; CUBIC LATTICES; DOPED MATERIALS; ELECTRONS; GROUND STATES; LANTHANUM COMPOUNDS; MANGANATES; OXYGEN; PHASE DIAGRAMS; PHASE TRANSFORMATIONS; STOICHIOMETRY; STRONTIUM COMPOUNDS; TEMPERATURE DEPENDENCE; TETRAGONAL LATTICES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION