Effects of magnetization on hole localization and MnO{sub 6} octahedra disorder in hole-doped lanthanum manganese perovskites
- Los Alamos National Lab., NM (United States)
- Univ. of California, Santa Cruz, CA (United States). Physics Dept.
- Florida Atlanta Univ., Boca Raton, FL (United States). Physics Dept.
The authors review the distortions of the MnO{sub 6} octahedra reduced by magnetization in hole-doped lanthanum manganese perovskites. The systems they consider include the colossal magnetoresistance (CMR) samples La{sub 1{minus}x}Ca{sub x}MnO{sub 3} (x = 0.21, 0.25, 0.30), La{sub 0.76}Ba{sub 0.33}MnO{sub 3}, and a poorer quality La{sub 0.76}Pb{sub 0.33}MnO{sub 3} sample. They also report preliminary work on three samples of oxygen-doped LaMnO{sub 3+{delta}} and a lanthanum-deficient La{sub 0.9}MnO{sub 3} sample. They find the same exponential relationship between the removal of the distortion and the sample magnetization in the Ba- and Pb-doped CMR samples as was found previously for the Ca doped samples. The MnO{sub 6} distortion in the oxygen-doped materials is found to slightly reduce below the magnetic transition, although much less so than in the CMR samples. Above T{sub C}, the antiferromagnetic LaMnO{sub 3.006} sample shows a softer temperature dependence of the Mn-O bond length distribution broadening. Surprisingly, even this sample shows deviations from thermal (Debye) behavior near T{sub N}, possibly due to FM coupling within MnO planes.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 296812
- Report Number(s):
- LA-UR-98-2531; CONF-9806129-; ON: DE99001242; TRN: 99:003074
- Resource Relation:
- Conference: Euroconference on polarons: condensation, pairing, magnetism, Erice (Italy), 9-17 Jun 1998; Other Information: PBD: [1998]
- Country of Publication:
- United States
- Language:
- English
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