Magnetic properties of Ni/NiO NPs

Several articles studying magnetic properties of Ni/NiO nanoparticles with different shapes and sizes:

 1) Synthesis, Alignment, and Magnetic Properties of Monodisperse Nickel Nanocubes.
Alec P. LaGrow, Bridget Ingham, Soshan Cheong, Grant V. M. Williams, Christian Dotzler, Michael F. Toney, David A. Jefferson, Elena C. Corbos, Peter T. Bishop, James Cookson, and Richard D. Tilley
JACS 134, 855 (2012)

(A) HRTEM image of a nickel nanocube. (B) High magnification of boxed area in (A) with NiO planes indexed.

2) Synthesis and Structural and Magnetic Characterization of Ni(Core)/NiO(Shell) Nanoparticles.
Aaron C. Johnston-Peck, Junwei Wang, and Joseph B. Tracy
ACS Nano 3, 1077 (2009) 

M vs H at 2.5 K for native and oxidized Ni(core)/NiO(shell) NPs after cooling from room temperature in 50 kOe field (FC) or zero field (ZFC).

3) Exchange-Bias and Grain-Surface Relaxations in Nanostructured NiO/Ni Induced by a Particle Size Reduction.
Aleksandar Kremenović, Boštjan Jančar, Mira Ristić, Milica Vučinić-Vasić, Jelena Rogan, Aleksandar Pačevski, and Bratislav Antić
J. Phys. Chem. C 116, 4356 (2012)