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This study focused on synthesizing AlNiCo and CoNi materials using a low-energy milling process. The aim was to explore the formation of low-energy phases in both systems, contrasting with the typical research on phases formed under high-energy conditions. In the Co-20 wt% Ni system, the phases Co 0.75 Ni 0.25 and Ni were identified, as well as the FCC cubic phase of CoNi, using X-ray diffraction (XRD) with a molybdenum radiation source. The observed behavior aligned closely with the miscibility curve in the equilibrium phase diagram, which included a region of alloys with varying structures and similar compositions. A notable feature was the presence of a predominantly dispersed hexagonal Ni zone, consisting of nanoparticles. Transmission electron microscopy (TEM) was employed to observe the FCC CoNi phase, which displayed a specific arrangement. AlNiCo and CoNi alloys were successfully synthesized through mechanical alloying, incorporating equilibrium and non-equilibrium phases. [ABSTRACT FROM AUTHOR]

This study focused on synthesizing AlNiCo and CoNi materials using a low-energy milling process. The aim was to explore the formation of low-energy phases in both systems, contrasting with the typical research on phases formed under high-energy conditions. In the Co-20 wt% Ni system, the phases Co0.75Ni0.25 and Ni were identified, as well as the FCC cubic phase of CoNi, using X-ray diffraction (XRD) with a molybdenum radiation source. The observed behavior aligned closely with the miscibility curve in the equilibrium phase diagram, which included a region of alloys with varying structures and similar compositions. A notable feature was the presence of a predominantly dispersed hexagonal Ni zone, consisting of nanoparticles. Transmission electron microscopy (TEM) was employed to observe the FCC CoNi phase, which displayed a specific arrangement. AlNiCo and CoNi alloys were successfully synthesized through mechanical alloying, incorporating equilibrium and non-equilibrium phases.

Co 100−x Ni x (x = 0, 10, 20, 30, …, 100) alloy nanostructures with controlled composition are prepared by hydrothermal method. The effects of composition on crystal structure, morphology, growth of nanostructure, and magnetic properties are described. The crystal structure is hexagonal closed pack (hcp) at x = 0, mixture of hcp and face-centered cubic (fcc) for 10 ≤ x ≤ 30, and purely fcc for x ≥ 40. The morphology is changed from nano-dendrite (x = 0) to flower like structure composed on spherical core and nanorods (x = 50) to nanosphere (x = 100). The isotropic (spherical shape) character increases with Ni Content. Compositional analyses show the controlled composition in nanostructure. The saturation magnetization is 156 emu/g at x = 0 and decreases linearly with alloy composition (x) to 55 emu/g at x = 100. The coercivity is 285 Oe at x = 0 (dendrite) and decrease gradually to 21 Oe at x = 80, and then increases to 146 Oe at x = 100. The effective anisotropy (K eff ) constant decreases gradually with alloy-composition and shows decaying exponential dependence on alloy-composition (x). Magnetic and structural properties are explained by combined consequences of composition and nanoscale effects. This study reveals that the composition of alloy plays important role in growth, morphology, crystal structure and hence, properties of nanostructure. [ABSTRACT FROM AUTHOR]

CoNi hollow-nanostructured microspheres are prepared by template-free hydrothermal method at low temperature (150 °C). The prepared CoNi nanostructures have face-centered cubic crystal lattice. Williamson-Hall analysis shows crystallite size of 55.5 nm and microstrain of 0.00265. Elemental mapping confirms the uniform distribution of Co and Ni atoms in sample. The size of hollow spheres is in the range of 1-3 μm which increase to 10 μm by increasing the reaction time. A stepwise growth mechanism based on time-dependent experiment is briefly described. The X-ray photoelectron spectroscopy analysis suggests the only metallic chemical state of Co and Ni in sample (no surface oxidation). The specific surface area of 80.56 m/g is obtained for 2 μm hollow sphere. The CoNi hollow-nanostructured microsphere shows 0.92 mass% hydrogen absorption and 81 % release of stored hydrogen. Hydrogen storage is attributed to crystal defects. The effects of morphology and surface area on hydrogen storage capacity and response are described. The saturation magnetization of 72.1 emu/g and coercivity of 157.21 Oe are observed for 2 μm hollow spheres. However, saturation magnetization of 77.5 emu/g and coercivity of 120 Oe are observed for 10 μm hollow spheres. The enhanced coercivity is related to surface and shape anisotropy due to hollow structure. [ABSTRACT FROM AUTHOR]

A sustainable 2D metal-based NiCo-based carbon nanosheet (CNs) material were synthesized via a template method and it was efficient for cleavage of C O ether bond in lignin. [Display omitted] • Sustainable approach for the production of NiCo-doped ultrathin CNs in one-step. • Cleavage of C O bond employing isopropanol as hydrogen-donor solvent. • Materials fabricated with cheap metal. This paper reports on a study of 2D metal-based (Ni-, NiCo-) carbon nanosheet (CNs) material that were synthesized via a template method and the synthetic materials showed an ultra-thin lamellar structure. The structures were characterized using different analytical methods including XRD, SEM, EDX, TEM, XPS, NH 3 -TPD. The synthesized NiCo-based CNs are ultrathin sheet shape with good crystallinity and uniform particle distributions. In the synthetic route of NiCo-based CNs, sodium lignosulfonate was employed as carbon and sulfur source and boric acid was used as 2D template to form a perfect lamellar structure. It manifested an environmentally-friendly and sustainable concept for preparation of the 2D NiCo-CNs. Although simple CNs was a poor catalyst, after Ni and NiCo doping, it became highly active in cleavage of β-O-4 ether bond in lignin through a catalytic transfer hydrogenation process and led to very high product yields. [ABSTRACT FROM AUTHOR]