Measurements of specific heat of the electron-doped La0.2 Ca0.8 MnO3 manganite are reported for 2<T<400 K. It was found that La0.2 Ca0.8 MnO3 exhibits an orbital ordering at TOO =204 K and a long-range antiferromagnetic order below TN =178 K. The entropy changes (ΔS) around both TOO [ΔS (TOO) ≈0.38 J/mol K] and TN [Δ S (TN) ≈3.58 J/mol K] were determined. The entropy change associated with the orbital ordering was found to be much smaller than that for charge ordered manganites. The low temperature specific heat indicates that La 0.2 Ca0.8 MnO3 has rather high Debye temperature D=685K in comparison with existing results for electron-doped La1-x Cax MnO3 manganites. Moreover, the presence of a large 1/ T2 hyperfine contribution and of a considerable linear term, unexpected for La0.2 Ca0.8 MnO3 with antiferromagnetic insulating ground state, was revealed. The possible relationship between the behavior of the heat capacity and the phase separation is discussed.
|Journal||Journal of Applied Physics|
|State||Published - 14 Apr 2010|
ASJC Scopus subject areas
- Physics and Astronomy (all)