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Structure, Magnetization and Resistivity of La$_{1-x}$M$_x$CoO$_3$ (M = Ca, Sr, and Ba)

M. Kriener·C. Zobel·A. Reichl·J. Baier·M. Cwik·K. Berggold·H. Kierspel·O. Zabara·A. Freimuth·T. Lorenz
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Abstract

We present an investigation of the influence of structural distortions in charge-carrier doped \lmco by substituting La$^{3+}$ with alkaline earth metals of strongly different ionic sizes, that is M = Ca$^{2+}$, Sr$^{2+}$, and Ba$^{2+}$, respectively. We find that both, the magnetic properties and the resistivity change non-monotonously as a function of the ionic size of M. Doping \lmco with M = Sr$^{2+}$ yields higher transition temperatures to the ferromagnetically ordered states and lower resistivities than doping with either Ca$^{2+}$ or Ba$^{2+}$ having a smaller or larger ionic size than Sr$^{2+}$, respectively. From this observation we conclude that the different transition temperatures and resistivities of \lmco for different M (of the same concentration $x$) do not only depend on the varying chemical pressures. The local disorder due to the different ionic sizes of La$^{3+}$ and M$^{2+}$ play an important role, too.

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M. Kriener, C. Zobel, A. Reichl, J. Baier, M. Cwik, K. Berggold, H. Kierspel, O. Zabara, A. Freimuth, T. Lorenz. 2004-01-21. Structure, Magnetization and Resistivity of La$_{1-x}$M$_x$CoO$_3$ (M = Ca, Sr, and Ba). https://doi.org/10.1103/physrevb.69.094417

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