Distinct insulating state below the Curie point in Pr 0
نویسندگان
چکیده
Magnetization, resistivity, thermal expansion, thermopower, and neutron powder diffraction data are presented for the perovskite manganite Pr0.7Ba0.3MnO3. A distinct ferromagnetic insulating state, similar to that observed in the La0.88Sr0.12MnO3 system, is observed in the temperature range between the paramagneticferromagnetic transition at TFM'180 K and the broad metal-insulator transition near Tp5120 K. The large A-site cation-size mismatch appears to suppress the ferromagnetic double-exchange interactions relative to the competing ferromagnetic superexchange interactions, thereby giving rise to the ferromagnetic insulating state.
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