Y. Nishihara

Metal–insulator transition in Fe-substituted SrRuO3 bad metal system

The effect of Fe substitution in the bad metal SrRuO3 perovskite was studied by resistivity, magnetic susceptibility and Mossbauer spectroscopic measurements. The conduction behavior changed from metallic for xFe≤0.1 to non-metallic for xFe>0.26. In the intermediate concentration range, 0.1<xFe<0.26, a resistivity minimum was observed as a function of temperature. The magnetic properties showed a change from ferromagnetic to paramagnetic for xFe≥0.3. There was an enhancement in quadrupole splitting deduced from 57Fe Mossbauer spectra in going from compositions xFe<0.3 to xFe≥0.3 suggestive of a change in screening of ionic charge at this composition. These observations show that the change in conduction behavior of this system may be related to the initial small mean free path of the bad metal system as well as a change in conduction electron density brought about by substitution of trivalent Fe for quadruvalent Ru.