Magnetic-Field Dependence Of Novel Gap Behavior Related To The Quantum-Size Effect

Pt-195-NMR measurements of Pt nanoparticles with a mean diameter of 4.0nm were performed in a high magnetic field of approximately mu H-0 = 23.3 T to investigate the low-temperature electronic state of the nanoparticles. The characteristic temperature T*, below which the nuclear spin-lattice relaxation rate 1/T-1 deviates from the relaxation rate of the bulk, shows a magnetic-field dependence. This dependence supports the theoretical prediction of the appearance of discrete energy levels.