Raman study of La/sub 2/CuO/sub 4/: Possibility of local symmetry breaking

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.36.7218· OSTI ID:5799927

Kourouklis, G A; Jayaraman, A; Weber, W; Remeika, J P; Espinosa, G P; Cooper, A S; Maines, Sr, R G

Raman spectra on flux-grown single crystals of La/sub 2/CuO/sub 4/ show two modes in the range of O stretch vibrations, near 426 and 526 cm/sup -1/. The latter line exhibits a very large intensity and has polarization features consistent with an in-plane O stretch vibration. The 426 cm/sup -1/ line is assigned to the axial O stretch mode, also found in superconducting La/sub 2-//sub x/(Ba,Sr)/sub x/CuO/sub 4/. The prominent 526 cm/sup -1/ line is observed over the temperature range from 77 to 600 K; i.e., even in the high-temperature tetragonal phase, where, by symmetry arguments, no in-plane O stretch mode is Raman allowed. We believe that the presence of this mode indicates local symmetry breaking, possibly due to antiferromagnetic fluctuations.

• Research Organization: ATandT Bell Laboratories, Murray Hill, New Jersey 07974
• OSTI ID: 5799927
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 36:13; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ANTIFERROMAGNETISM
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
CRYSTALS
HIGH TEMPERATURE
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LOW TEMPERATURE
MAGNETISM
MEDIUM TEMPERATURE
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
RAMAN SPECTRA
RARE EARTH COMPOUNDS
SPECTRA
SYMMETRY BREAKING
TRANSITION ELEMENT COMPOUNDS