Nanocriticality in the magnetic phase transition of CoO nanoparticles

Machteld E. Kamminga, Jonas Okkels Birk, Jari Hjøllum, Henrik Jacobsen, Jakob Lass, Thorbjørn L. Koch, Niels B. Christensen, Christof Niedermayer, Lukas Keller, Luise Theil Kuhn, Elisabeth T. Ulrikkeholm, Erik Brok, Cathrine Frandsen, Kim Lefmann*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

5 Downloads (Pure)


The universal theory of critical phase transitions describes the critical behavior at second-order phase transitions in infinitely large systems. With the increased contemporary interest in nanoscale materials, we investigated CoO nanoparticles by means of neutron scattering and found how the theory of critical phenomena breaks down in the nanoscale regime. Using CoO as a model system, we have identified a size-dependent nanocritical temperature region close to the antiferromagnetic phase transition where the magnetic correlation length of the nanoparticles converges to a constant value, which is significantly smaller than that of the saturated state found at low temperatures. This is in clear contrast to the divergence around TN observed for bulk systems. Our finding of nanocriticality in the magnetic phase transition is of great importance for the understanding of phase transitions at the nanoscale.
Original languageEnglish
Article number064424
JournalPhysical Review B
Issue number6
Number of pages6
Publication statusPublished - 2023


Dive into the research topics of 'Nanocriticality in the magnetic phase transition of CoO nanoparticles'. Together they form a unique fingerprint.

Cite this