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

Journal Article · Wed Jun 24 04:00:00 EDT 2015 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4917580· OSTI ID:22490182

Shahee, Aga; Lalla, N. P. ^[1]

---

1. UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore (M.P)-452001 (India)

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.

• OSTI ID: 22490182
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1665; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

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