Growth and properties of superconducting anisotropic lead nanoprisms

Anisotropic Pb nanoprisms were synthesized using high-temperature polyol reduction of lead acetylacetonate through a kinetically controlled synthesis. Transmission electron microscopy showed that the majority of the prisms grows along {111} planes. Selected area electron diffraction (SAED) on single prism revealed that the anisotropic growth is due to twinning in the growing nuclei. Magnetic measurements on a colloidal deposited film exhibited a large magnetic hysteresis that is due to the penetration and pinning of magnetic flux. This flux trapping behavior could be due to a possible transition from type I to type II superconductor given the finite thickness of the prisms (< 100 nm) or from the currents flowing in a network of coupled prisms.