Collective dynamics of 2D ferromegnetic element arrays

Review: Magneto.optical measurements of collective spin dynamics of two-dimensional arrays of ferromagnetic elements.
Bivas Rana and Anjan Barman
Spin 3, 1330001(2013) 

(a) Simulated resonant modes for an array of 200nm square dots with 100nm interdot separations are plotted as a
function of the azimuthal angle ( ) of the bias field. (b) Powerand phase distributions of the simulated modes are shown for
four di®erent values of . The color scales are shown at the top right corner of the figure.

New route to nanocrystal synthesis: galvanic replacement

All change for nanocrystals.
Maria Ibáñez and Andreu Cabot
Science 340, 935 (2013)

Galvanic Replacement Reactions in Metal Oxide Nanocrystals.
Myoung Hwan Oh, Taekyung Yu, Seung-Ho Yu, Byungkwon Lim, Kyung-Tae Ko,Marc-Georg Willinger, Dong-Hwa Seo, Byung Hyo Kim, Min Gee Cho, Jae-Hoon Park, Kisuk Kang, Yung-Eun Sung, Nicola Pinna, Taeghwan Hyeon
Science 340, 964 (2013)

Schematic illustration of the transformation of Mn3O4 NCs, showing the evolution of their morphology via the localized dissolution of Mn3O4 and the surface precipitation of g-Fe2O3. (B to E) HRTEM images of the hollow nanostructures synthesized by the reaction of Mn3O4 NCs with 1 ml of aqueous solutions of iron(II) perchlorate having different concentrations.

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.