Macroscopic quantum tunneling in PdO nanoparticles

TL;DR

This study investigates PdO nanoparticles at low temperatures, revealing macroscopic quantum tunneling behavior through magnetic measurements and identifying key temperature-dependent phenomena.

Contribution

It provides the first evidence of macroscopic quantum tunneling in PdO nanoparticles by detailed magnetic characterization and analysis of relaxation behaviors.

Findings

Peak at 50 K in ZFC mode indicating blocking temperature

Magnetization decrease below 36 K suggests quantum tunneling

Particle size estimated at approximately 5.07 nm

Abstract

We studied the physical behavior of PdO nanoparticles at low temperatures, which presents an unusual behavior clearly related to macroscopic quantum tunneling. The samples show a tetragonal single phase with P42/mmc space group. Most importantly, the particle size was estimated at about 5.07 nm. Appropriate techniques were used to determine the characteristic of these nanoparticles. The most important aspect of this study is the magnetic characterization performed at low temperatures. It shows a peak at 50 K in zero field cooling mode (ZFC) that corresponds to the Blocking temperature (T$_{B}$). These measurements in ZFC and field cooling (FC) indicates that the peak behavior is due to different relaxation times of the asymmetrical barriers when the electron changes from a metastable state to another. Below T$_{B}$ in FC mode, the magnetization decreases with temperature until 36 K; this temperature is the crossover temperature (T$_{Cr}$) related to the anisotropy of the barriers, indicative of macroscopic quantum tunneling.