Due to the unique properties of core/shell particles, these structures have been considered in various applications. Employing core/shell particles consisting of a polymer core and a ceramic shell as an abrasive in a chemical mechanical planarization (CMP) process enhanced the quality of processed wafers. In the present study, polystyrene/silica core/shell particles were synthesized and the elastic modulus was examined via atomic force microscopy (AFM). The impact of the indentation depth and contact mechanics models on the elastic modulus was studied. Also, the plastic properties of particles were examined for the first time. Using the Hertz model and a diamond-like carbon (DLC) probe, the elastic moduli of the polymer and core/shell particles were measured at 2.82 ± 0.03 and 6.53 ± 0.05 GPa, respectively.

Atomic Force Microscopes (AFMs) have been widely used as nanomanipulators due to their versatility to work with a broad range of materials and their controllable interaction force, among other features. While AFMs can effectively grasp, move, and position nanoscale objects in 2D environments through basic pull/push operations, they often lack the high precision required in many 3D pick and place applications, especially in non-vacuum environments. In this study, a novel method to resolve the adhesion problem between nanoscale objects and the AFM tip has been developed and tested. The method is based on the application of a high electrostatic voltage to the tip to produce the repulsive force required for the release of the nanoobject. The method is proposed for conductive nanoparticles and tips used in many nanomanipulation applications, and can be easily implemented on typical AFMs with minimal alterations. The applicability of the proposed method is investigated through a series of combined Molecular Dynamics/Finite Element simulations.

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In this research, hard/soft CoFe 2 O 4 /Ni magnetic nanocomposite samples with different concentrations of Ni were successfully produced by a two-step mechanical alloying route. Single-phase CoFe 2 O 4 (CFO), having the average particle size of 35 nm, saturation magnetization of 71 emu/g, and bandgap energy of 2.6 eV was synthesized via the mechanical alloying method. A mixture of as-synthesized CFO and 10, 30 and, 50 wt. % Ni powder has been severely milled to prepare magnetic nanocomposite samples. The effects of different Ni content on the characteristics of the nanocomposite samples have been investigated. FESEM images showed that the ductile nickel powder particles get flattened after 1 h milling, whereas the brittle CFO particles get fragmented by increasing milling time to 10 h. The single-phase-like hysteresis loop, and the switching field distribution curves alongside the simultaneous enhancements of maximum energy product and remanence reflect the presence of exchange spring phenomenon in the nanocomposite samples. Also, the diffuse reflectance spectroscopy (DRS) analysis evidence the reduction of bandgap energy for 10 wt.% Ni containing nanocomposite sample from 2.44 to 2.15 eV on increasing the milling time from 1 to 10 h. Under the optimum photocatalyst operating conditions, the CFO/10 wt% Ni sample exhibited the highest photocatalytic activity of 93.6% for methylene blue (MB) degradation in comparison with the cobalt ferrite sample. Eventually, the detailed kinetic and mechanism to describe the improvement of the photocatalytic performance were suggested.

Barium carbonate (BaCO3) nano-particles were synthesized from the mixture of Ba(OH)2.8H2O and Na2CO3 by mechano-chemical route without any subsequent heat treatment of the as-milled powders. Effects of milling time and addition of process control agents (PCA) on the phase composition and morphology of products have been investigated. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that BaCO3 nano-particles were synthesized only after 10 minutes of mechanical milling and phase evolution was not taken place by further milling. SEM results indicated that pencil-like and globular-like were two major morphologies of the particles. Addition of stearic acid as a PCA resulted in homogenized globular-like nano-particles with a mean particle size of 54 nm.