Elastic and vibrational properties of monoclinic HfO2 from first-principles study

Abstract The elastic and vibrational properties of crystalline monoclinic HfO 2 have been investigated using density functional perturbation theory. Using the Voigt and Reuss theory, we estimate the bulk, shear and Young's modulus for polycrystalline HfO 2 , which agree very well with the available experimental and theoretical data. Additionally, we present a systematic analysis of the elastic properties of HfO 2 polymorphs and find the trends in the elastic parameters for the HfO 2 structures are consistent with those for the ZrO 2 structures. The choice of exchange-correlation functional has an important effect on the results of elastic and vibrational properties. The utilization of Hartwigzen–Goedecker–Hutter type functional is a great improvement on calculation of the zone-centre phonon frequencies, and shows the root-mean-square absolute deviation of 7 cm −1 with experiments. A rigorous assignment of all the Raman modes is achieved by combining symmetry analysis with the first-principles calculations, which helps us to identify the main peak and some other features of Raman spectra. Furthermore, the Raman spectrum of HfO 2 powder has been simulated for the first time, providing a theoretical benchmark for the interpretation of the unresolved problems in experimental studies.