skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: First-principles based calculation of the macroscopic α/β interface in titanium

Abstract

The macroscopic α/β interface in titanium and titanium alloys consists of a ledge interface (112){sub β}/(01-10){sub α} and a side interface (11-1){sub β}/(2-1-10){sub α} in a zig-zag arrangement. Here, we report a first-principles study for predicting the atomic structure and the formation energy of the α/β-Ti interface. Both component interfaces were calculated using supercell models within a restrictive relaxation approach, with various staking sequences and high-symmetry parallel translations being considered. The ledge interface energy was predicted as 0.098 J/m{sup 2} and the side interface energy as 0.811 J/m{sup 2}. By projecting the zig-zag interface area onto the macroscopic broad face, the macroscopic α/β interface energy was estimated to be as low as ∼0.12 J/m{sup 2}, which, however, is almost double the ad hoc value used in previous phase-field simulations.

Authors:
 [1];  [2]; ;  [1];  [1];  [2];  [2];  [2]
  1. School of Materials Science and Engineering, Central South University, Changsha 410083 (China)
  2. (China)
Publication Date:
OSTI Identifier:
22596799
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 22; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; FORMATION HEAT; INTERFACES; RELAXATION; SIMULATION; SYMMETRY; TITANIUM; TITANIUM ALLOYS

Citation Formats

Li, Dongdong, Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083, Zhu, Lvqi, Shao, Shouqi, Jiang, Yong, E-mail: yjiang@csu.edu.cn, Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083, National Key Lab for Powder Metallurgy, Central South University, Changsha 410083, and Shenzhen Research Institute of Central South University, Shenzhen 518057. First-principles based calculation of the macroscopic α/β interface in titanium. United States: N. p., 2016. Web. doi:10.1063/1.4953381.
Li, Dongdong, Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083, Zhu, Lvqi, Shao, Shouqi, Jiang, Yong, E-mail: yjiang@csu.edu.cn, Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083, National Key Lab for Powder Metallurgy, Central South University, Changsha 410083, & Shenzhen Research Institute of Central South University, Shenzhen 518057. First-principles based calculation of the macroscopic α/β interface in titanium. United States. doi:10.1063/1.4953381.
Li, Dongdong, Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083, Zhu, Lvqi, Shao, Shouqi, Jiang, Yong, E-mail: yjiang@csu.edu.cn, Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083, National Key Lab for Powder Metallurgy, Central South University, Changsha 410083, and Shenzhen Research Institute of Central South University, Shenzhen 518057. 2016. "First-principles based calculation of the macroscopic α/β interface in titanium". United States. doi:10.1063/1.4953381.
@article{osti_22596799,
title = {First-principles based calculation of the macroscopic α/β interface in titanium},
author = {Li, Dongdong and Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083 and Zhu, Lvqi and Shao, Shouqi and Jiang, Yong, E-mail: yjiang@csu.edu.cn and Key Lab of Nonferrous Materials of Ministry of Education, Central South University, Changsha 410083 and National Key Lab for Powder Metallurgy, Central South University, Changsha 410083 and Shenzhen Research Institute of Central South University, Shenzhen 518057},
abstractNote = {The macroscopic α/β interface in titanium and titanium alloys consists of a ledge interface (112){sub β}/(01-10){sub α} and a side interface (11-1){sub β}/(2-1-10){sub α} in a zig-zag arrangement. Here, we report a first-principles study for predicting the atomic structure and the formation energy of the α/β-Ti interface. Both component interfaces were calculated using supercell models within a restrictive relaxation approach, with various staking sequences and high-symmetry parallel translations being considered. The ledge interface energy was predicted as 0.098 J/m{sup 2} and the side interface energy as 0.811 J/m{sup 2}. By projecting the zig-zag interface area onto the macroscopic broad face, the macroscopic α/β interface energy was estimated to be as low as ∼0.12 J/m{sup 2}, which, however, is almost double the ad hoc value used in previous phase-field simulations.},
doi = {10.1063/1.4953381},
journal = {Journal of Applied Physics},
number = 22,
volume = 119,
place = {United States},
year = 2016,
month = 6
}
  • The epitaxial integration of functional oxides with wide band gap semiconductors offers the possibility of new material systems for electronics and energy conversion applications. We use first principles to consider an epitaxial interface between the correlated metal oxide SrRuO{sub 3} and the wide band gap semiconductor TiO{sub 2}, and assess energy level alignment, interfacial chemistry, and interfacial dipole formation. Due to the ferromagnetic, half-metallic character of SrRuO{sub 3}, according to which only one spin is present at the Fermi level, we demonstrate the existence of a spin dependent band alignment across the interface. For two different terminations of SrRuO{sub 3},more » the interface is found to be rectifying with a Schottky barrier of ≈1.3–1.6 eV, in good agreement with experiment. In the minority spin, SrRuO{sub 3} exhibits a Schottky barrier alignment with TiO{sub 2} and our calculated Schottky barrier height is in excellent agreement with previous experimental measurements. For majority spin carriers, we find that SrRuO{sub 3} recovers its exchange splitting gap and bulk-like properties within a few monolayers of the interface. These results demonstrate a possible approach to achieve spin-dependent transport across a heteroepitaxial interface between a functional oxide material and a conventional wide band gap semiconductor.« less
  • The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. A method for calculating and subsequently tuning the electrochemical potential of a half cell using periodic plane-wave density functional theory and a homogenous counter-charge is presented and evaluated by comparison to simulations which explicitly model the countercharge by a plane of ions. The method involves the establishment of two reference potentials, one related to the potential of the free electronmore » in vacuo, and the other related to the potential of H₂O species far from the electrode. The surface potential can be specifically adjusted by the explicit introduction of excess or deficit surface charges in the simulation cell and the application of periodic boundary conditions. We demonstrate the absence of field emission from the electrode over the range of realistic electrochemical potentials covered and confirm that the method can explicitly determine reaction energies and adsorption geometries as a function of electrochemical potential. This latter point is most useful as it asserts the viability of this method to model electrochemical and electrocatalytical systems of academic as well as applied interest. We present two case studies. The first examines the changes in the structure of water at the metal interface as a function of potential over Cu(111). At cathodic potential, we observe the repulsion of H₂O from the interface and the rotation of the water dipole toward the interface. The second study follows the initial pathways for the electrocatalytical activation of methanol over Pt(111) and the corresponding potential dependent reaction energetics for these paths. The results demonstrate that changes in the electrochemical potential can significantly alter the reaction energetics as well as the overall reaction selectivity. While the case studies presented herein described equilibrium geometries (i.e., the ideal forms at zero kelvin), the method is also suitable for application to ensembles of thermally activated systems.« less
  • The α-WC(0001) surface and β-SiC(111)/α-WC(0001) interface were studied by first-principles calculation based on density functional theory. It is demonstrated that the α-WC(0001) surface models with more than nine atom-layers exhibit bulk-like interior, wherein the surface relaxations localized within the top three layers are well converged. Twenty-four specific geometry models of SiC/WC interface structures with different terminations and stacking sites were chosen. The calculated work of adhesion and interface energy suggest that the most stable interface structure has the C-C bonding across the interface, yielding the largest work of adhesion and the lowest interface energy. Moreover, the top-site stacking sequence ismore » preferable for the C/C-terminated interface. The effects of the interface on the electronic structures of the C/C-terminated interfaces are mainly localized within the first and second layers of the interface. Calculations of the work of adhesion and interface energy provide theoretical evidence that the mechanical failure may initiate at the interface or in SiC but not in WC.« less
  • The theoretical average voltage, energy density (energy per volume), and specific energy (energy per mass) based on the active electrode material have been calculated from first principles for two types of rechargeable lithium-ion batteries. In the charged state the two batteries consist of LiC{sub 6} and Mo{sub 2} electrodes (M = Mo and Ni). The calculation was performed using the linearized augmented plane wave crystal code WIEN95 based on density functional theory (DFT). The structure was calculated by varying the unit cell volume of the experimentally known crystallographic data with respect to the total energy. The calculated results are comparedmore » with measured values. The temperature dependence of the average voltage, energy density, and specific energy was demonstrated to be of minor importance. In the case of the LiC{sub 6}/NiO{sub 2} battery this was done by calculating the vibrational energy contribution to the enthalpy change using the cluster approximation and the Amsterdam density functional (ADF) molecular code based on DFT. The agreement between theoretical and experimental values opens up the use of first principles quantum chemistry in battery technology.« less
  • We present a first-principles method for the determination of the van der Waals interactions for a collection of finite-sized macroscopic bodies. The method is based on fluctuational electrodynamics and a rigorous multiple-scattering method for the electromagnetic field. As such, the method takes fully into account retardation, many-body, multipolar, and near-fields effects. By application of the method to the case of two metallic nanoparticles, we demonstrate the breakdown of the standard 1/r{sup 2} distance law as the van der Waals force decays exponentially with distance when the nanoparticles are too close or too far apart.