Effect of compositional fluctuations on the phase transitions in (Nd{sub 1/2}Sr{sub 1/2})MnO{sub 3}

Journal Article · Wed Dec 01 04:00:00 EST 1999 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm990281d· OSTI ID:20014834

Woodward, P M; Cox, D E; Vogt, T; Rao, C N.R.; Cheetham, A K

High-resolution synchrotron X-ray and neutron powder diffraction techniques have been used to investigate the structural and magnetic phase and magnetic phase transitions in two polycrystalline samples with nominal composition (Nd{sub 0.5}Sr{sub 0.5})MnO{sub 3}. The first sample separates into three coexisting macroscopic phases at low temperature: a ferromagnetic (FM) phase, an orbitally ordered antiferromagnetic A-type (AFM-A) phase, and the majority phase, which shows charge, orbital, and antiferromagnetic CE-type (AFM-CE) ordering. The second sample shows a clean transition from the FM state into the AFM-CE state. The unusual behavior of the first sample is associated with a slight excess of Mn{sup 4+} and a wider compositional range with respect to the second sample and illustrates the very delicate competition between these three states near a Mn{sup 4+}:Mn{sup 3+} ratio of unity, where both electron delocalization and charge-ordering are known to occur. The charge-ordered structure of Nd{sub 0.5}Sr{sub 0.5}MnO{sub 3} is reported.

• Research Organization: Ohio State Univ., Columbus, OH (US)
• Sponsoring Organization: US Department of Energy; National Institute of Standards and Technology
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 20014834
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 12 Vol. 11; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
CRYSTAL-PHASE TRANSFORMATIONS
MANGANESE OXIDES
NEODYMIUM OXIDES
PEROVSKITES
STRONTIUM OXIDES