Evidence for Multiple Phase Transitions in La_1-xCa_xCoO_3

M. Kriener; M. Braden; D. Senff; O. Zabara; T. Lorenz

doi:10.1016/j.jmmm.2006.10.529

Evidence for Multiple Phase Transitions in La_1-xCa_xCoO_3

Strongly Correlated Electrons 2008-01-28 v1

Authors: M. Kriener , M. Braden , D. Senff , O. Zabara , T. Lorenz

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Abstract

We report thermal-expansion and specific-heat data of the series La_1-xCa_xCoO_3 for 0 <= x <= 0.3. For x = 0 the thermal-expansion coefficient alpha(T) features a pronounced maximum around T = 50 K caused by a temperature-dependent spin-state transition from a low-spin state (S=0) at low temperatures towards a higher spin state of the Co^3+ ions. The partial substitution of the La^3+ ions by divalent Ca^2+ ions causes drastic changes in the macroscopic properties of LaCoO_3. Around x ~ 0.125 the large maximum in alpha(T) has completely vanished. With further increasing x three different anomalies develop.

Keywords

thermal expansion specific heat spin-state transition La1-xCaxCoO3 phase transitions cobaltates

Cite

@article{arxiv.cond-mat/0605721,
  title  = {Evidence for Multiple Phase Transitions in La_1-xCa_xCoO_3},
  author = {M. Kriener and M. Braden and D. Senff and O. Zabara and T. Lorenz},
  journal= {arXiv preprint arXiv:cond-mat/0605721},
  year   = {2008}
}

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