Abstract
We report a combined Raman-scattering and electron spin resonance (ESR) study of the metallic triangular compound along with lattice dynamic calculations. Our Raman data reveal (i) an exponential increase of the 706 cm mode involving the out-of-plane motions of the oxygen atoms and (ii) electronic Raman scatterings whose scattering rate is strongly suppressed as the temperature approaches K. The temperature dependence of the ESR linewidth is described by a critical broadening with the exponent . These are interpreted in terms of coherence of interplane hoppings along the axis and a reconstruction of electronic bands on approaching . Our results suggest a significant role of an interference between metallic and magnetic layers in explaining collective excitations in .
- Received 3 February 2014
DOI:https://doi.org/10.1103/PhysRevB.90.045122
©2014 American Physical Society