Work

Curie-Weiss behavior and the interaction temperature of magnetic nanoparticle ensembles: Local structure strongly affects the magnetic behavior

Year: 2024

Type: article

Abstract: In this article, the Curie-Weiss type behavior and the appearance of an ``interaction'' or ``ordering'' temperature for a collection of magnetic nanoparticles is explored theoretically. We show that some systems where an interaction temperature is reported are too dilute for dipolar interactions to play a role unless at least some of the particles are clumped together. We then show using the most simple type of clumps (particle pairs) that positive and negative interaction temperatures are possible due to dipolar interactions. The clump orientation dramatically changes this result. Finally, we show that an apparent interaction temperature can be measured in magnetic nanoparticle systems that have no interactions between particles, due to some alignment of anisotropy easy axes. These results show that nanoscale physical structures affect the measured magnetic response of nanoparticles.

Source: Physical review. B./Physical review. B

DOI: 10.1103/physrevb.110.144440

Authors: Robert E. Camley, Rair Macêdo, Karen L. Livesey

Institutions: University of Colorado Colorado Springs, University of Glasgow, University of Newcastle Australia

Language: English

Topic: Characterization and Applications of Magnetic Nanoparticles

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: US-UK Fulbright Commission, Fulbright Australia, University of Newcastle Australia

OpenAlex ID: W4403683409