@article{2fa823e3239e4a3381e4686a040fea4a,
title = "Nanocriticality in the magnetic phase transition of CoO nanoparticles",
abstract = "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. ",
author = "Kamminga, {Machteld E.} and Birk, {Jonas Okkels} and Jari Hj{\o}llum and Henrik Jacobsen and Jakob Lass and Koch, {Thorbj{\o}rn L.} and Christensen, {Niels B.} and Christof Niedermayer and Lukas Keller and Kuhn, {Luise Theil} and Ulrikkeholm, {Elisabeth T.} and Erik Brok and Cathrine Frandsen and Kim Lefmann",
note = "Funding Information: We thank N. H. Andersen, B. Lebech, P.-A. Lindg{\aa}rd, J. Juul, and H. Bruus for stimulating discussions. A large thank you goes to S. M{\o}rup for participating in the initial phases of this project. We thank H. M. R{\o}nnow for providing access to the Quantum Wolf computer cluster at the Laboratory for Quantum Magnetism, EPFL, Lausanne. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sk{\l}odowska-Curie Grant Agreement No. 838926. H.J. acknowledges support from the Carlsberg Foundation. This work was supported by the Danish Technical Research Council through the Nanomagnetism framework program and by the Danish Natural Science Research Council through DANSCATT. The work is based on experiments performed at SINQ, Paul Scherrer Institute, Villigen, Switzerland. Publisher Copyright: {\textcopyright} 2023 authors. Published by the American Physical Society.",
year = "2023",
doi = "10.1103/PhysRevB.107.064424",
language = "English",
volume = "107",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "6",
}