MAGNETIC AND CONDUCTIVE PROPERTIES OF LA0.5PB0.5MNO3

The magnetic and conductive properties of polycrystalline La0.5Pb0.5Mn O3 containing similar to 13at.% of a second phase Pb3Mn6O13, a ere inv estigated. The studies reported include measurements of magnetization, electrical resistivity and magnetoresistance, in a temperature range 10 divided by 400 K and at applied magnetic fields up to 5 Tesla. It w as found that the sample exhibits a ferromagnetic ordering with relati vely low coercive field at room temperature. Measurements of field-coo led and reversed-field-cooled magnetization support models of coexisti ng magnetic phases in ferromagnetic La-based manganites. The resistivi ty measured exhibits a maximum at similar to 230 K and a broad shallow minimum at similar to 20 divided by 25 K. These features are also att ributed to the temperature dependence of the magnetic inhomogeneities. Measurements of magnetoresistance show a characteristic giant effect at low temperatures.