John Ferrante

Bio: John Ferrante is an academic researcher from Glenn Research Center. The author has contributed to research in topics: Surface energy & Binding energy. The author has an hindex of 26, co-authored 111 publications receiving 6335 citations. Previous affiliations of John Ferrante include ExxonMobil.

Universal features of the equation of state of metals

Abstract: The zero-temperature equation of state of metals, in the absence of phase transitions, is shown to be accurately predicted from zero-pressure data. Upon appropriate scaling of experimental pressure-volume data a simple universal relation is found. These results provide further experimental confirmation of the recent observation that the total-binding-energy---versus---separation relations for metals obey a universal scaling relation. Important to our results is a parameter $\ensuremath{\eta}$, which is a measure of the anharmonicity of a crystal. This parameter is shown to be essential in predicting the equation of state. A simple formula is given which predicts the zero-temperature derivative of the bulk modulus with respect to pressure.

Universal features of the equation of state of solids

Abstract: A study of the energetics of solids leads to the conclusion that the equation of state for all classes of solids in compression can be expressed in terms of a universal function. The form of this universal function is determined by scaling experimental compression data for measured isotherms of a wide variety of solids. The equation of state is thus known (in the absence of phase transitions), if zero-pressure volume and isothermal compression and its pressure derivative are known. The discovery described in this paper has two immediate consequences: first, despite the well known differences in the microscopic energetics of the various classes of solids, there is a single equation of state for all classes in compression; and second, a new method is provided for analyzing measured isotherms and extrapolating high-pressure data from low-pressure (e.g. acoustic) data.

Universal binding energy curves for metals and bimetallic interfaces

Abstract: We provide evidence for a universal relationship between metallic binding energies and lattice parameters. By a simple scaling of a universal relationship, one can obtain binding energies as a function of atomic separation for bimetallic interfaces and bulk metals.

A universal equation of state for solids

Abstract: The total energy versus interatomic spacing of ionic, metallic, covalent, and rare-gas solids is examined, and a universal form for pressure as a function of volume for all classes of solids in compression is derived. The relation is shown to hold for pressure-volume data for hydrogen and deuterium, xenon, cesium, molybdenum, sodium chloride, and magnesium oxide.

Universal features of bonding in metals

Abstract: Binding-energy-distance relations for metallic systems are shown to exhibit a universal behavior under a simple two-parameter scaling. All currently available ab initio calculations for the cohesion and adhesion of metals, as well as the chemisorption of gas atoms on metal surfaces, are shown to be determined by this single relation. Further, the energetics of diatomic molecules are determined by the same relation, despite the existence of strong volume-dependent forces for metals. These findings suggest a commonality of metallic bonding and a close relationship between molecular and metallic bonding. The universal nature of binding-energy-distance relations implies relations between seemingly disparate physical phenomena. As an example we show that the surface-binding-energy relation can be approximately expressed in terms of the bulk quantities. This leads to an explanation of the well-known empirical result that the surface energy per surface atom is proportional to the cohesive energy per bulk atom. Also, a simple relationship between adsorbate-substrate vibrational stretch frequencies and their desorption energies follows from the universal relationship.

Embedded-atom-method functions for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, and their alloys.

Abstract: A consistent set of embedding functions and pair interactions for use with the embedded-atom method [M.S. Daw and M. I. Baskes, Phys. Rev. B 29, 6443 (1984)] have been determined empirically to describe the fcc metals Cu, Ag, Au, Ni, Pd, and Pt as well as alloys containing these metals. The functions are determined empirically by fitting to the sublimation energy, equilibrium lattice constant, elastic constants, and vacancy-formation energies of the pure metals and the heats of solution of the binary alloys. The validity of the functions is tested by computing a wide range of properties: the formation volume and migration energy of vacancies, the formation energy, formation volume, and migration energy of divacancies and self-interstitials, the surface energy and geometries of the low-index surfaces of the pure metals, and the segregation energy of substitutional impurities to (100) surfaces.

First principles phonon calculations in materials science

Abstract: Phonon plays essential roles in dynamical behaviors and thermal properties, which are central topics in fundamental issues of materials science. The importance of first principles phonon calculations cannot be overly emphasized. Phonopy is an open source code for such calculations launched by the present authors, which has been world-widely used. Here we demonstrate phonon properties with fundamental equations and show examples how the phonon calculations are applied in materials science.

Numerical simulations of fast crack growth in brittle solids

Abstract: Dynamic crack growth is analysed numerically for a plane strain block with an initial central crack subject to tensile loading. The continuum is characterized by a material constitutive law that relates stress and strain, and by a relation between the tractions and displacement jumps across a specified set of cohesive surfaces. The material constitutive relation is that of an isotropic hyperelastic solid. The cohesive surface constitutive relation allows for the creation of new free surface and dimensional considerations introduce a characteristic length into the formulation. Full transient analyses are carried out. Crack branching emerges as a natural outcome of the initial-boundary value problem solution, without any ad hoc assumption regarding branching criteria. Coarse mesh calculations are used to explore various qualitative features such as the effect of impact velocity on crack branching, and the effect of an inhomogeneity in strength, as in crack growth along or up to an interface. The effect of cohesive surface orientation on crack path is also explored, and for a range of orientations zigzag crack growth precedes crack branching. Finer mesh calculations are carried out where crack growth is confined to the initial crack plane. The crack accelerates and then grows at a constant speed that, for high impact velocities, can exceed the Rayleigh wave speed. This is due to the finite strength of the cohesive surfaces. A fine mesh calculation is also carried out where the path of crack growth is not constrained. The crack speed reaches about 45% of the Rayleigh wave speed, then the crack speed begins to oscillate and crack branching at an angle of about 29° from the initial crack plane occurs. The numerical results are at least qualitatively in accord with a wide variety of experimental observations on fast crack growth in brittle solids.