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Author Shahee, Aga ♦ Lalla, N. P.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword 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
Abstract 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.
ISSN 0094243X
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-06-24
Publisher Place United States
Volume Number 1665
Issue Number 1


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