Evaluation of Raman scattering in La{sub 1{minus}x}M{sub x}MnO{sub 3} single crystals due to structural and magnetic transitions
Book
·
OSTI ID:323428
- National Inst. of Standards and Technology, Gaithersburg, MD (United States). Optical Technology Div.
- Univ. of Maryland, College Park, MD (United States). Dept. of Physics
The study of doped and undoped La{sub 1{minus}x}M{sub x}MnO{sub 3} single crystals (x = 0 to x = 0.3) in the temperature range from 5 K to 423 K is reported. The activity of phonon vibrational modes in optical spectra is analyzed and a comparison to experimental Raman data is presented. Different contributions from optical phonons to the Raman scattering process are discussed. It is shown that both the value of doping and temperature have a significant influence on Raman features, and these are strongly affected by structural and magnetic phase transitions. Due to the symmetry present in distorted lanthanum manganese compounds their Raman spectra were found to contain comparable contributions from first- and second-order phonon scattering. The common features related to both the reduction of the Jahn-Teller (JT) distortion and the temperature-induced phase transition were found in the Raman spectra of La{sub 1{minus}x}M{sub x}MnO{sub 3} crystals. An anomalous behavior of the low-frequency Raman mode in doped system was found and explained in terms of the temperature-dependent ionic radius of the La/Sr ion sites. It was found that the strong dependence of the A{sub g} Raman mode on the value of doping may serve as a useful tool for optical characterization of La{sub 1{minus}x}M{sub x}MnO{sub 3} compounds, including the inhomogeneity of the surface.
- OSTI ID:
- 323428
- Report Number(s):
- CONF-971201--; ISBN 1-55899-399-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Local Jahn-Teller distortion in La{sub 1{minus}x}Sr{sub x}MnO{sub 3} observed by pulsed neutron diffraction
Volume contraction and resistivity drop at the Jahn-Teller transition in La{sub 1-x}Ca{sub x}MnO{sub 3}
Evidence of local lattice distortions in La{sub 1{minus}x}Sr{sub x}MnO{sub 3} provided by pulsed neutron diffraction
Journal Article
·
Wed Oct 01 00:00:00 EDT 1997
· Physical Review, B: Condensed Matter
·
OSTI ID:632651
Volume contraction and resistivity drop at the Jahn-Teller transition in La{sub 1-x}Ca{sub x}MnO{sub 3}
Journal Article
·
Tue Feb 28 23:00:00 EST 2006
· Physical Review. B, Condensed Matter and Materials Physics
·
OSTI ID:20787965
Evidence of local lattice distortions in La{sub 1{minus}x}Sr{sub x}MnO{sub 3} provided by pulsed neutron diffraction
Journal Article
·
Mon Mar 31 23:00:00 EST 1997
· Journal of Applied Physics
·
OSTI ID:544301