Optimal T-C layered manganites : different roles of coherent and incoherent lattice distortions.

Journal Article · Sun Aug 01 00:00:00 EDT 1999 · Phys. Rev. Lett.

DOI:https://doi.org/10.1103/PhysRevLett.83.1223· OSTI ID:942628

Medarde, M; Mitchell, J F; Millburn, J E; Short, S; Jorgensen, J D

Neutron powder diffraction experiments on layered manganites La{sub 2-2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} (0.32{<=}x{<=}0.40) show that coherent lattice anomalies observed at the Curie temperature (lattice parameters, Mn-O bond lengths) reverse sign at x{approx}0.36, coinciding with the maximum T{sub c}{approx}131 K. Remarkably, the anomalies are completely suppressed at this crossover composition. Incoherent distortions, as measured by anisotropic Debye-Waller factors, undergo an abrupt decrease below T{sub c}. The magnitude of this anomaly changes very little with x and does not display any sign reversal for x{approx}0.36.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC); FOR
• DOE Contract Number: DE-AC02-06CH11357
• OSTI ID: 942628
• Report Number(s): ANL/MSD/JA-33166; PRLTAO; TRN: US200920%%19
• Journal Information: Phys. Rev. Lett., Vol. 83, Issue 6 ; Aug. 1999; ISSN 0031-9007
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
BOND LENGTHS
CURIE POINT
DEBYE-WALLER FACTOR
NEUTRON DIFFRACTION
LANTHANUM OXIDES
LATTICE PARAMETERS
MANGANESE OXIDES
STRONTIUM OXIDES
TRANSITION TEMPERATURE