Comment on "Raman spectroscopy study of Nax Co O2 and superconducting Nax Co O2 y H2 O"
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
75
Journal Issue
10
Date Issued
2007
Author(s)
Abstract
The effect of surface degradation of the thermolectric cobaltite on Raman spectra is discussed and compared to experimental results from Co3 O4 single crystals. We conclude that on NaCl-flux grown Nax Co O2 crystals a surface layer of Co3 O4 easily forms that leads to the observation of an intense phonon around 700 cm-1. The Raman spectra on freshly cleaved crystals from optical floating zone ovens do not show such effects and have a high-frequency phonon cutoff at approximately 600 cm-1. We discuss the relation of structural dimensionality, electronic correlations, and the high-frequency phonon cutoff of the thermolectric cobaltite. © 2007 The American Physical Society.
Type
journal article