Neutron and x-ray evidence of charge melting in ferromagnetic layered colossal magnetoresistance manganites (invited)
Recent x-ray and neutron scattering studies have revealed static diffuse scattering due to polarons in the paramagnetic phase of the colossal magnetoresistive manganites La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7}, with x=0.40 and 0.44. We show that the polarons exhibit short-range incommensurate correlations that grow with decreasing temperature, but disappear abruptly at the combined ferromagnetic and metal{endash}insulator transition in the x=0.40 system because of the sudden charge delocalization, while persisting at low temperature in the antiferromagnetic x=0.44 system. The {open_quotes}melting{close_quotes} of the polaron ordering as we cool through T{sub C} occurs with the collapse of the polaron scattering itself in the x=0.40 system. This short-range polaron order is characterized by an ordering wave vector q=(0.3,0,1) that is almost independent of x for x{ge}0.38, and is consistent with a model of disordered stripes. {copyright} 2001 American Institute of Physics.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40203890
- Journal Information:
- Journal of Applied Physics, Vol. 89, Issue 11; Other Information: DOI: 10.1063/1.1365256; Othernumber: JAPIAU000089000011006840000001; 486111MMM; PBD: 1 Jun 2001; ISSN 0021-8979
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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