Finite size effect on Neel temperature with Co3O4 nanoparticles

TL;DR

This study investigates how reducing the size of Co3O4 nanoparticles affects their Neel temperature, revealing a finite size scaling behavior and quantifying key parameters like the shift exponent and bulk transition temperature.

Contribution

It provides experimental evidence of finite size effects on Neel temperature in Co3O4 nanoparticles and determines the scaling parameters governing this relationship.

Findings

Neel temperature decreases with nanoparticle size

Finite size scaling relation fits experimental data

Shift exponent and correlation length are quantified

Abstract

Finite size effect on the antiferromagnetic transition temperature, TN, of Co3O4 nanoparticles of 75, 35, and 16 nm in diameter, has been investigated. The AFM transition point, TN, reduces with the decreasing diameter, d. Along with the results from the previous experiments on the Co3O4 nanoparticles of 8 and 4.3 nm, the variation of TN with d appears to follow the finite size relation. According to the scaling behavior, the shift exponent is determined as \lambda = 1.4 \pm 0.4, the correlation length, \ksi_0 = 3.0 \pm 0.3 nm, and the bulk Neel temperature, TN(\infint) = 38.6 \pm 0.7 K.