The effect of hydrostatic pressure on structural, piezoelectric and dielectric properties of wurtzite and zinc-blende BeO crystals with DFT-DFPT calculations

An in-depth look at the structural, electronic, optical, and thermal properties of the cubic Be x Mg y Zn1−x−y O quaternary alloys

“…Besides, the lattice of BeO compound found to be equal to 3.80 Å and 3.83 Å from WC-GGA and PBE-GGA approach, respectively. The same values were found by Duman [45] and Almaghbash [43], respectively. This similarity should be justified by the use of the same exchange-correlation functionals.…”

“…It is pertinent to note the existence of a noticeable lack of both theoretical and empirical results pertaining to the ternary and quaternary alloys under consideration, with the exception of theoretical data pertaining to the ternary alloy Mg 0.5 Zn 0.5 O [34]. In contrast, our findings of binary compounds ZnO, BeO, and MgO exhibit a noteworthy agreement with the results of previous theoretical and experimental investigations documented in the scientific literature [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48].…”

Strain-induced giant enhancement of anisotropic dielectric constant in layered nitrides SrHfN2 and SrZrN2

“…The DFPT implemented in the VASP 5,6 was used to calculate the macroscopic dielectric tensors e and the Born effective charge tensors. [36][37][38][39][40] The dielectric tensor includes electronic (e ele ) and ionic (e ion ) contributions (e = e ele + e ion ), and the static e r can be obtained by averaging the diagonal components of e. Furthermore, the ionic contribution to e r is also defined as the lattice-vibrational component: [38][39][40]…”

“…The DFPT implemented in the VASP 5,6 was used to calculate the macroscopic dielectric tensors ε and the Born effective charge tensors. 36–40 The dielectric tensor includes electronic ( ε ele ) and ionic ( ε ion ) contributions ( ε = ε ele + ε ion ), and the static ε r can be obtained by averaging the diagonal components of ε . Furthermore, the ionic contribution to ε r is also defined as the lattice-vibrational component: 38–40 where e is the electron charge, m 0 is a reference mass, Ω is the unit-cell volume, ω λ is the frequency of the λ th infrared (IR) active phonon mode, and α and β denote the Cartesian coordinates, respectively.…”

Elastic and piezoelectric properties of β-glycine – a quantum crystallography view on intermolecular interactions and a high-pressure phase transition

“…Such studies make it possible to predict mechanical, thermodynamic and optoelectronic properties, as well as phase transitions of various types. Piezoelectric properties of crystals under pressure were studied for some inorganic crystals, such as wurtzite (Marana et al, 2017;Almaghbash & Arbouche, 2021), potassium niobate (Faridi et al, 2018;Stash et al, 2021) and others (Daoud, 2019;Mubarak & Tariq, 2021). However, to the best of our knowledge, molecular crystals were not considered from this point of view yet.…”