Magnetic-Field Dependence of Novel Gap Behavior Related to the Quantum-Size Effect

TL;DR

This study uses high-field NMR to explore how magnetic fields influence the electronic states of platinum nanoparticles, revealing discrete energy levels consistent with quantum-size effects at low temperatures.

Contribution

It provides experimental evidence of magnetic-field dependence of gap behavior in nanoparticles, supporting theoretical predictions of discrete energy levels due to quantum confinement.

Findings

$T^*$ decreases with increasing magnetic field.

Deviation of $1/T_1$ from bulk behavior observed below $T^*$.

Results support the quantum-size effect theory.

Abstract

$^{195}$Pt-NMR measurements of Pt nanoparticles with a mean diameter of 4.0 nm were performed in a high magnetic field of approximately $\mu_0 H = 23.3$ 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.