Magnetic and electronic properties of lead-doped lanthanum manganate

Materials of nominal composition La1–xPbxMnO3 (0.0≤x≤0.4) prepared by prolonged annealing at 950 °C, have been characterised by a combination of powder X-ray diffraction, energy dispersive X-ray microanalysis, thermogravimetry, atomic absorption spectroscopy and oxidising-power analysis. All phases adopt a rhombohedral variant of the perovskite structure and show significant deviations from nominal stoichiometries. All doped materials exhibit ferromagnetic ordering at a temperature, TC , close to ambient and undergo a metal–insulator transition at a temperature, TMI , close to TC . Both TC and TMI show greater compositional variation than previously reported.