Multi-spin-state dynamics during insulator-metal crossover in LaCoO3.

Authors :: Doi, A.
Fujioka, J.
Fukuda, T.
Tsutsui, S.
Okuyama, D.
Taguchi, Y.
Arima, T.
Baron, A. Q. R.
Tokura, Y.
Source :: Physical Review B: Condensed Matter & Materials Physics. Aug2014, Vol. 90 Issue 8, p081109-1-081109-4. 4p.
Publication Year :: 2014
Abstract: We have investigated the dynamics of spin-state crossover (SSC) for perovskite LaCoO3 through optical phonons by means of infrared and inelastic x-ray spectroscopy. Upon thermally induced SSC, anomalously dispersionless Co-0 bond stretching phonons coupled to the thermally excited spin state have been identified. The enhanced spin-state fluctuation irrespective of the presence of a clear charge gap suggests the emergence of complex spin-state disproportionation involving low-, intermediate-, and high-spin states due to the strong correlation among thermally activated spin states. [ABSTRACT FROM AUTHOR]