Particle size-dependent superspin glass behavior in random compacts of monodisperse maghemite nanoparticles - IOPscience

Particle size-dependent superspin glass behavior in random compacts of monodisperse maghemite nanoparticles.
Mikael Svante Andersson, Roland Mathieu, Peter S Normile, Su Seong Lee, Gurvinder Singh, Per Nordblad and Jose Angel De Toro
Materials Research Express 3, 045015 (2016)

 Temperature-dependent (normalized to the maximum of near the onset of dissipation) data replotted as a function of reduced temperature , where the denominator is the temperature of maximum slope of for each sample (h = 80 A m⁻¹, f = 10 Hz).

Superantiferromagnetism in NPs

Size-induced superantiferromagnetism with reentrant spin-glass behavior in metallic nanoparticles of TbCu2.
C. Echevarria-Bonet, D. P. Rojas, J. I. Espeso, J. Rodríguez Fernández,1 L. Rodríguez Fernández, P. Gorria, J. A. Blanco, M. L. Fdez-Gubieda, E. Bauer, G. André, and L. Fernández Barquín
Phys. Rev. B 87, 180407 (2013)

Thermomagnetic DC-susceptibility ZFC curves obtained with magnetic fields, 1 kOe H 10 kOe, where
the evolution from AF to SG state can be observed. A FC curve is also plotted at H = 1 kOe to evidence the irreversibility. Inset (bottom): Linear Tf variation vs H2/3. Inset (top): ZFC DC susceptibility of the alloy at a pressure P = 1.1 GPa.

Super SG behavior in interacting NPs

Superspin glass originating from dipolar interaction with controlled interparticle distance among γ -Fe2O3 nanoparticles with silica shells.
Kosuke Hiroi, Katsuyoshi Komatsu, and Tetsuya Sato
Phys. Rev. B 83, 224424 (2011)

Temperature-dependent magnetization of the samples L12, L14, L18, and L34 under ZFC and FC conditions.
All curves are normalized by the value in Tpeak in the ZFC condition.

See also the article:

Do 8 nm Co Nanocrystals in Long-Range-Ordered Face-Centered Cubic (fcc) Supracrystals Show Superspin Glass Behavior?
Dinah Parker, Isabelle Lisiecki, and M. P. Pileni
J. Phys. Chem. Lett. 1, 1139 (2010)