High-temperature ferromagnetism and super-high-temperature superconductivity in Pb-O nanoparticles

Abstract

Near-spherical, platelet, and chip-shaped Pb-O nanoparticles (NPs) ranging in average particle sizes from 50 up to 450 nm were prepared by using the modified jet aerosol method through condensation of metallic lead vapor in He gas flow with an oxygen injection. SEM, XRD, BET, and VSM were used for the characterization of the nanoparticles. The room-temperature ferromagnetism with a maximum saturation magnetization up to 8.7 emu/g was recorded in the nanoparticles. NPs with maximum magnetization possessed a certain unit cell volume of Pb and PbO components. The maximum saturation magnetization value of NPs was achieved when the PbO content was approx. 9–15%. In situ high-temperature VSM measurements showed that magnetization stored up to temperatures of 870–970 K. By heat treatment of the NPs up to 670 K, a diamagnetic contribution in the total magnetization was also discovered, which might have attributed to the existence of some local superconductive areas.