Abstract
We present an investigation of the influence of structural distortions in charge-carrier doped by substituting with alkaline-earth metals of strongly different ionic sizes, that is, and respectively. We find that both the magnetic properties and the resistivity change nonmonotonically as a function of the ionic size of M. Doping with yields higher transition temperatures to the ferromagnetically ordered states and lower resistivities than doping with either or having a smaller or larger ionic size than respectively. From this observation we conclude that the different transition temperatures and resistivities of for different M (of the same concentration do not only depend on the varying chemical pressures. The local disorder due to the different ionic sizes of and plays an important role, too.
- Received 21 August 2003
DOI:https://doi.org/10.1103/PhysRevB.69.094417
©2004 American Physical Society