title: Meissner effect in colloidal Pb nanoparticles.
abstract: Monodisperse colloidal lead nanoparticles with diameters ranging from 4.4 to 20 nm are prepared by a self-limiting growth method. The nanoparticles are monodispersed and protected from oxidation by an amorphous tin-lead oxide shell of 1.5-2 nm thickness. The magnetic susceptibility of the particles is measured as a function of size, temperature, and magnetic field. The Meissner effect is observed indicating the superconducting transition. For the 20 and 16 nm particles, the critical temperature is suppressed to 6.9 K from the bulk value of 7.2 K and is further reduced for smaller particles. Depending on the size of the particles, the critical field is enhanced by 60-140 times. The superconducting properties agree closely with the theoretical expectations.
authors.affiliation: James Franck Institute, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Pavlo
authors.initials: P
authors.lastname: Zolotavin
authors.forename: Philippe
authors.initials: P
authors.lastname: Guyot-Sionnest
mesh_terms: D003102:Colloids / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010825:Physics / Q000379:methods; D013696:Temperature; D014001:Tin / Q000737:chemistry
chemical_list: D003102:Colloids; D008024:Ligands; D008670:Metals; D010087:Oxides; D007854:Lead; C047365:lead oxide; D014001:Tin; D010100:Oxygen