Magnetic Properties of Small Magnetite Nanocrystals

Abstract

This paper focuses on the study of the magnetic properties of 9 nm magnetite nanocrystals. XRD and TEM measurements indicate the presence of crystalline particles, with a fraction of them only partially crystallized or highly defective. The analysis of the temperature dependence of the zero-field-cooled/field-cooled magnetization and of the thermoremanent magnetization provides evidence of the existence of three magnetic regimes: a high temperature regime (300–100 K), an intermediate regime (100–20 K), and a low temperature regime (below 20 K). The characteristics of such regimes are discussed.