The hodograph equation for slow and fast anisotropic interface propagation

Using the model of fast phase transitions and previously reported equation of the Gibbs–Thomson-type, we develop an equation for the anisotropic interface motion of the Herring–Gibbs–Thomson-type. The derived equation takes the form of a hodograph equation and in its particular case describes motion by mean interface curvature, the relationship ‘velocity—Gibbs free energy’, Klein–Gordon and Born–Infeld equations related to the anisotropic propagation of various interfaces. Comparison of the present model predictions with the molecular-dynamics simulation data on nickel crystal growth (obtained by Jeffrey J. Hoyt et al. and published in Acta Mater. 47 (1999) 3181) confirms the validity of the derived hodograph equation as applicable to the slow and fast modes of interface propagation. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

Formation of Standing Waves Within Crystal Unitcell

We show that the historic Davisson-Germer experiment demonstrates formation of standing waves within nickel crystal unitcell. Cartesian Fourier transform cannot offer description in terms of standing waves because Cartesian Fourier theory cannot accommodate π in place of 2π. Thus, formation of standing waves within unitcell in Davisson-Germer experiment necessarily requires spherical polar coordinate description of crystal diffraction. Description in spherical polar coordinates permits to incorporate precision angles from the experiment for better convergence in structure determination calculations.

Electron Matter-Waves as Electromagnetically Induced Crystal Oscillator Effects

The famed Davisson-Germer Experiments demonstrated the wave phenomenon of electrons similarly to X-Ray scattering from Sir Lawrence Bragg’s X-ray experimentations on crystals c. 1913. Their empirical deduction of electrons behaving as waves (i.e. oscillatory) ignores the possibility of an electron beam behaving harmonically upon elastic collision with a diffraction grating - represented by nickel crystal - in their experiment. However, it is well established in the electrical engineering science that crystals possess piezoelectric effects and are used ubiquitously in electronic circuit designs for causing stable harmonic oscillation responses to direct current voltages. In light of this, the current mathematical model proposes the Davisson-Germer results to be the effect of a nickel crystal oscillator circuit which amplifies a direct voltage source – the electron beam – causing the phenomenon of inductance from the resultant electrical feedback with the crystal atom’s electromagnetic field.

Surface Morphology and Texture of Nickel Crystal Micro-Casting by Electroforming under Magnetic Field

Micro-components were electroplated using composite electroforming technology under magnetic field. The surface morphology of the micro components was examined using scanning electron microscope (SEM) and X-ray spectrometer was used to detect texture. The results show that: the texture and surface morphology of the micro components are influenced by the current density and the magnetic field intensity. With the increase of current density, the size of crystal grains decrease firstly but increase later .And as the increase of the magnetic field intensity, the size of crystal grains become smaller and more uniform. Besides, the current density and the magnetic field intensity have a great impact on the texture of castings. As the increase of the current density, the texture orientation changes from (111) to (200). At the same time, along with the increase of the magnetic field intensity, the diffraction peak (200) is suppressed while the diffraction peak (111) is enhanced obviously.

Synthesis and Characterization of Graphite-Encapsulated Metal (Fe,Co,Ni) Nanoparticles by a Detonation Method

A method for synthesizing carbon-encapsulated metal nanoparticles(CEMNPs) is reported. In the proposed method, a composite precursors containing various nitrate dissolved in absolute ethanol is ignited by a nonelectric detonator in nitrogen gas in an explosion vessel. Upon the completion of detonation reaction, CEMNPs (Fe@C, Ni@C, Co@C) with diameters ranging from a few nanometers to about 20 nm are produced in the explosion vessel.The material characteristics of these nanoparticles are then examined with the XRD, TEM, EDX and VSM, which characterize the feature of morphology, components, phases and magnetism of nano-composite particles. The composite particles whose coating shell were graphite carbon could be dispersed finely. The core of nanoparticles were composed of iron,cobalt and nickel crystal to that of the above explosive precursors.The magnetic analysis indicated that the different composite nanoparticles have good ferromagnetism and superparamagetism in room temperature.

Synthesis of Carbon-Encapsulated Metal (Fe,Co,Ni) Nanoparticles by Detonation Decomposition of Composite Explosives

A detonation method for synthesizing carbon-encapsulated metal nanoparticles (CEMNPs) is reported. The composite precursors containing various nitrate dissolved in absolute ethanol is ignited by a nonelectric detonator in nitrogen gas in an explosion vessel. The material characteristics of these nanoparticles are then examined with the XRD,TEM,EDX and RS. The results show that the composite particles whose coating shell were graphite carbon could be dispersed finely. The core of nanoparticles were composed of iron, cobalt and nickel crystal to that of the above explosive precursors.