A sonochemistry-based synthesis method was used to produce nanocrystalline nickel oxide powder with ≈ 20 nm average crystallite diameter from Ni(OH)(2) precursor. Ultrasound waves were applied to the primary solution to intensify the Ni(OH)(2) precipitation. Dried precipitates were calcined at 320°C to form nanocrystalline NiO particles. The morphology of the produced powder was characterized b...

We have obtained the magnetic field dependence of static ferromagnetic correlations in nanocrystalline electrodeposited Co and Ni by means of the correlation function of the spin misalignment, determined from small-angle neutron scattering data. The approach yields a correlation length l(C), which is a measure for the spatial extent of inhomogeneities in the magnetization distribution. The corr...

Systematic experiments have been performed to investigate the rate sensitivity of deformation in fully dense nanocrystalline Ni using two different experimental techniques: depth-sensing indentation and tensile testing. Results from both types of tests reveal that the strain-rate sensitivity is a strong function of grain size. Specifically microcrystalline and ultra-fine crystalline pure Ni, wi...

Amorphous powder of composition corresponding to Ni60Ti20Zr20 (in at%) was obtained by ball milling in a high-energy mills starting from pure elements. Formation of the amorphous structure was observed already after 20 h of milling, although complete amorphization occurred after 40 h. The microhardness of powders increased from about 30 HV for pure elements to above 400 HV (1290 MPa) after 40 h...

Article history: Received 15 June 2016 Received in revised form 9 July 2016 Accepted 9 July 2016 Available online 20 July 2016 Multicomponent alloying can be utilized to enhance the thermal stability of nanocrystalline alloys. The grain boundary energy can be reduced significantly via both bulk and grain-boundary high-entropy effects with increasing temperature at/within the solid solubility li...

Macroscopic strain was hitherto considered a necessary corollary of deformation twinning in coarse-grained metals. Recently, twinning has been found to be a preeminent deformation mechanism in nanocrystalline face-centered-cubic (fcc) metals with medium-to-high stacking fault energies. Here we report a surprising discovery that the vast majority of deformation twins in nanocrystalline Al, Ni, a...

It is believed that the dynamics of dislocation processes during the deformation of nanocrystalline materials can only be visualized by computational simulations. Here we demonstrate that observations of dislocation processes during the deformation of nanocrystalline Ni with grain sizes as small as 10 nm can be achieved by using a combination of in situ tensile straining and high-resolution tra...

Kaub, T., Felfer, P., Cairney, J., Thompson, G. (2016). Influence of Ni Solute segregation on the intrinsic growth stresses in Cu(Ni) thin films. Scripta Materialia, 113, 131-134. [Mor e Information] He, M., Samudrala, S., Kim, G., Felfer, P., Breen, A., Cairney, J., Gianola, D. (2016). Linking stress-driven microstructural evolut...

Nanocrystalline Ni-W alloys having both high ductility and high strength were produced by electrodeoisition. The plating bath for the electrodeposition contained nickel sulfate, citric acid, sodium tungstate and ammonium chloride, and was operated at various bath concentrations and conditions of electrolysis. The ductility and tensile strength of the deposited alloys are strongly influenced by ...