Lattice dynamics of Nd2CuO4
Abstract
We present a lattice-dynamical treatment of Nd2CuO4 (T' structure) in the framework of a shell model that is based on short-range overlap and long-range Coulomb potentials, and includes ionic polarizabilities. We have formulated the static equilibrium conditions for the T' structure under this interaction model, and use the equilibrium conditions to determine the potential parameters for some of the unknown short-range interactions (e.g., Nd-O). Two versions of the shell model are used in the calculation: model I (``generic'' model), which was developed without reference to any experimental phonon-dispersion data of Nd2CuO4, and model II, which involved some fitting to the experimental data. In addition to the phonon-dispersion curves, we present results for the phonon density of states F(ω) and the phonon specific heat cv(T). We discuss the low-temperature behavior of cv(T) by examining cv(T)/T3 and FTHETA(T) in the range between 0 and 40 K.
- Publication:
-
Physical Review B
- Pub Date:
- October 1993
- DOI:
- 10.1103/PhysRevB.48.10143
- Bibcode:
- 1993PhRvB..4810143R
- Keywords:
-
- 74.72.Jt;
- 63.20.Dj;
- 65.40.Em;
- 78.30.-j;
- Other cuprates including Tl and Hg-based cuprates;
- Phonon states and bands normal modes and phonon dispersion;
- Infrared and Raman spectra