Meissner Effect in Colloidal Pb Nanoparticles

作者：Zolotavin Pavlo; Guyot Sionnest Philippe^*

来源：ACS Nano, 2010, 4(10): 5599-5608.

DOI：10.1021/nn102009g

• superconductivity
• grains
• Meissner effect
• magnetic susceptibility
• critical field
• transition temperature
• monodisperse
• metal nanoparticles
• lead
• colloidal
• oxidation
• core-shell

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.

• 出版日期2010-10