Experimental confirmation of Zener-polaron-type charge and orbital ordering in Pr{sub 1-x}Ca{sub x}MnO{sub 3}

Journal Article · Thu Nov 01 00:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.76.174210· OSTI ID:21052749

Wu, L; Zhu, Y ^[1]; Klie, R F ^[1]; Jooss, Ch ^[2]

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1. Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

Pr{sub 1-x}Ca{sub x}MnO{sub 3} in the doping range between 0.3<x<0.5 represent an extremely interesting manganite system for the study of the interplay of different kinds of ordering (charge, orbital, lattice, and spin). While there is consensus that a charge- and orbital-ordered state develops below a transition temperature T{sub co}{approx_equal}230 K, recent controversial structural refinements resulting from neutron and x-ray diffraction studies challenged our understanding of the particular type of charge ordering (CO) and orbital ordering (OO), and consequently, the underlying mechanism of the colossal resistance effects. Here, we present a detailed high-resolution transmission electron microscopy and electron-diffraction study that, based on extinction rules, resolves the current controversy and confirms the existence of the Zener-polaron (ZP)-type CO and/or OO in Pr{sub 1-x}Ca{sub x}MnO{sub 3}. The ZP-type ordering is further verified by atomic-column-resolved electron energy-loss spectroscopy revealing strong charge ordering of the in-plane oxygen-Mn bonds, while valence disproportionation at the Mn sites is less than expected. Over wide doping and temperature ranges, we observed structural phase coexistence between the ZP-CO/OO P2{sub 1}nm and the disordered Pbnm structure.

• OSTI ID: 21052749
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 76, Issue 17; Other Information: DOI: 10.1103/PhysRevB.76.174210; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALCIUM COMPOUNDS
CARBON MONOXIDE
ELECTRON DIFFRACTION
ELECTRONS
ENERGY-LOSS SPECTROSCOPY
MANGANATES
NEUTRON DIFFRACTION
NEUTRONS
ORTHORHOMBIC LATTICES
OXIDATION
OXYGEN
POLARONS
PRASEODYMIUM COMPOUNDS
REDUCTION
SPACE GROUPS
SPIN
TEMPERATURE RANGE
TRANSITION TEMPERATURE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION