2016 ◽  
Vol 850 ◽  
pp. 348-353 ◽  
Author(s):  
Hai Jun Hou ◽  
Hao Guan ◽  
Shun Ru Zhang ◽  
Lin Hua Xie ◽  
Lei Wang

The structural, electronic, phonon and thermodynamic properties of rocksalt (RS) structure LiF are studied using a plane-wave pseudopotential method within the local density approximation (LDA). The values of lattice constants, elastic constants, and bulk modulus and its pressure derivatives are in well agreement with the available experimental data and other theoretical results. The LiF crystal exhibits a wide band gap of about 8.727 eV. The linear response method is applied to determine the phonon dispersion, phonon density of states and Born effective charge. The phonon frequencies at the Γ, X, L points are analyzed using group theory. We also calculate the thermodynamic functions such as free energy, enthalpy, entropy, specific heat using the phonon density of states. We compare the present calculation results satisfactorily to experimental and previous theoretical results.


1989 ◽  
Vol 03 (08) ◽  
pp. 1277-1286 ◽  
Author(s):  
JIE QIN ◽  
YIMIN JIANG

We have presented a lattice dynamical calculation of phonon dispersion curves and one-phonon density of states for the high-T c superconducting MBa 2 Cu 3 O x (M=Y, Gd : x=7, 6) compounds. The model we used is in the framework of a rigid-ion model which includes long-range Coulomb potential and a short-range overlap. The results of calculation give quite good agreement with the available Raman and infrared data, and the measurements of phonon density of states. These results therefore can serve as a guide for further experimental investigations of the phonon properties in M-Ba-Cu-O (M=rare earth atom) system.


2019 ◽  
Vol 21 (44) ◽  
pp. 24684-24694 ◽  
Author(s):  
I. R. Shein ◽  
V. V. Novikov ◽  
S. V. Kuznetsov ◽  
K. V. Ponkratov ◽  
A. V. Matovnikov ◽  
...  

The phonon dispersion and phonon density of states of LuB2C (Pbam) show the absence of negative phonon frequencies, i.e. this system is dynamically stable.


Sign in / Sign up

Export Citation Format

Share Document