scholarly journals Tunability of High-Dielectric-Constant Materials from First Principles

2002 ◽  
Vol 718 ◽  
Author(s):  
K. M. Rabe
Keyword(s):  
Dielectric Constant ◽  
Perturbation Theory ◽  
First Principles ◽  
Density Functional ◽  
High Dielectric Constant ◽  
Leading Order ◽  
Density Functional Perturbation Theory ◽  
High Dielectric Constant Materials ◽  
High Dielectric ◽  
First Principles Method

AbstractA first-principles method, based on density functional perturbation theory, is presented for computing the leading order tunability of high-dielectric-constant materials.

Hydrogenation as a source of superconductivity in two-dimensional TiB2

2021 ◽  
pp. 2150057
Author(s):  
Hui Wang ◽  
Chen Pan ◽  
Sheng-Yan Wang ◽  
Hong Jiang ◽  
Yin-Chang Zhao ◽  
...  
Keyword(s):  
Perturbation Theory ◽  
Vibration Frequency ◽  
First Principles ◽  
Density Functional ◽  
Tensile Strain ◽  
2D Materials ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Density Functional Perturbation Theory ◽  
Potential Applications

Using first-principles calculations based on density functional perturbation theory, we demonstrate hydrogenation-induced superconductivity in monolayer TiB2H. Hydrogen adatoms destroy the Dirac state of monolayer TiB2 and monolayer TiB2H has a high vibration frequency. Monolayer TiB2H is a phonon-mediated superconductor. Monolayer TiB2H has a predicted [Formula: see text] of 8[Formula: see text]K, which further increases under external tensile strain. Thus, this study extends our understanding of superconductivity in two-dimensional (2D) materials and its potential applications.

First-Principles Study of Structural and Vibrational Properties of α-SiO2 under Pressure

2015 ◽  
Vol 775 ◽  
pp. 191-196
Author(s):  
Xiao Wei Lei ◽  
Yong Song ◽  
Kuo Yang ◽  
Hui Zhao
Keyword(s):  
High Pressure ◽  
Perturbation Theory ◽  
Infrared Spectra ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Vibrational Properties ◽  
Vibrational Modes ◽  
Density Functional Perturbation Theory ◽  
Good Agreement

Using first principles approach, we present the structural, vibrational and dielectric properties of α-SiO2. The calculations have been carried out within the density functional perturbation theory and linear response formalism using the norm-concerving pseudopotentials and a plane wave basis. All the vibrational modes identified are in good agreement with experiment. The calculated infrared spectra are also in good agreement with available experimental results both for the positions and the intensities of the main peaks. We find that the modes Eu7 and A2u4 splits in two respectively at high hydrostaticpressures. Then we calculate the infrared spectra under high pressure of different orientations. The vibrational modes in different phase transitions are reported and discussed respectively.

First-principle studies of the lattice dynamics of crystals, and related properties

2005 ◽  
Vol 220 (5/6) ◽  
Author(s):  
Xavier Gonze ◽  
Gian-Marco Rignanese ◽  
Razvan Caracas
Keyword(s):  
Perturbation Theory ◽  
First Principles ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Computational Method ◽  
Dielectric Tensor ◽  
Atomic Temperature ◽  
Density Functional Perturbation Theory ◽  
Infra Red ◽  
Temperature Factors

AbstractThe crystal lattice is never rigid. Due to temperature, external fields or pressure, the nuclei vibrate, the lattice distorts, and instabilities can induce phase transitions. We review the basic concepts of density-functional perturbation theory, a computational method especially suited to determine from first-principles the microscopic parameters governing such behaviour. Then, we present the additional formalism leading to the following properties of minerals: the infra-red and Raman spectra; the prediction of (meta)stability or instability of a crystalline phase, based on the phonon spectrum; the computation of thermodynamics quantities like the free energy, entropy, specific heat; the atomic temperature factors. For each property, examples are given. When appropriate, we mention the computation of related properties, like dielectric tensor and Born effective charges that are needed to get infra-red spectra. Finally, we discuss briefly, on one hand, other applications of the density-functional perturbation theory, and, on the other hand, an alternative technique, the finite-difference computation of dynamical matrices.

Engineering High Dielectric Constant Materials for Band-Edge CMOS Applications

2019 ◽  
Vol 16 (5) ◽  
pp. 19-26 ◽  
Author(s):  
Hemanth Jagannathan ◽  
Vijay Narayanan ◽  
Stephen Brown
Keyword(s):  
Dielectric Constant ◽  
High Dielectric Constant ◽  
Band Edge ◽  
High Dielectric Constant Materials ◽  
High Dielectric

ABSORPTION IN A DIELECTRIC SLAB

1958 ◽  
Vol 36 (4) ◽  
pp. 456-461 ◽  
Author(s):  
M. P. Bachynski
Keyword(s):  
Dielectric Constant ◽  
Incident Energy ◽  
High Dielectric Constant ◽  
Angle Of Incidence ◽  
Dielectric Slab ◽  
Absorbed Energy ◽  
Half Wavelength ◽  
High Dielectric Constant Materials ◽  
High Dielectric ◽  
Electrical Thickness

The amount of incident energy transmitted, reflected, and absorbed by a parallel slab of lossy, high-dielectric-constant material is derived. The results are general for any angle of incidence, and calculations are presented for some lossy, high-dielectric-constant materials of one-half wavelength electrical thickness. At angles of incidence greater than 60°, the reflected energy is found to be the smaller the lossier the material. The absorbed energy is a maximum at certain angles of incidence which depend upon the polarization and dielectric constant.

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