Structural, electronic, and optical properties for the cubic, tetragonal, and monoclinic crystalline phases of Zr O2, as derived from ab initio full-relativistic calculations, are presented. The electronic structure calculations were carried out by means of the all-electron full-potential linear augmented plane wave method, within the framework of the density functional theory and the local density approximation. The calculated carrier effective masses are shown to be highly anisotropic. The results obtained for the real and imaginary parts of the dielectric function, the reflectivity, and the refraction index show good agreement with the available experimental results. In order to obtain the static dielectric constant of Zr O2, we added to the electronic part the optical phonon contribution, which leads to values of 1 (0) ≃29.5,26.2,21.9, respectively, along the xx, yy, and zz directions, for the monoclinic phase, in excellent accordance with experiment. Relativistic effects, including the spin-orbit interaction, are demonstrated to be important for a better evaluation of the effective mass values and in the detailed structure of the frequency dependent complex dielectric function.
Bibliographical noteFunding Information:
We acknowledge support from the Brazilian funding agencies, CNPq, FAPESP, and FAPEMIG. One of the authors (S.C.P.R.) would like to acknowledge the scholarship from the project CT-ENERG/CNPq (Grant No. 503.570/03-6).