Lattice dynamics of orthorhombic perovskite yttrium manganite, YMnO₃

Abstract

The lattice dynamics of yttrium manganite (YMnO(3)) has been investigated by means of a shell model with pair-wise interionic interaction potential. The experimental data of crystal structure and Raman and infrared frequencies compare well with the lattice dynamical calculations. The phonon dispersion curves found along three high symmetry directions and the density of states of YMnO(3) have also been calculated from this model. The computed phonon density of states is used to derive the macroscopic thermodynamic quantities like the Debye temperature and specific heat. The crystal structure data computed from this model are in good agreement with the available experimental data measured by neutron powder diffraction. We have made a comparative study of the structures derived from the potential model calculations for both LaMnO(3) and YMnO(3). Symmetry vectors obtained through group theoretical analysis at the zone centre point were employed to classify the phonon frequencies obtained into their irreducible representations. The computed Raman and infrared frequencies have shown good agreement with the measured data.

Spin-phonon coupling and high-temperature phase transition in multiferroic material YMnO3

“…It was concluded that YMnO 3 is an improper ferroelectric. Various theoretical and experimental attempts have been made to understand the anomalous properties of YMnO3 as well as to understand the mechanism of phase transitions, multiferroicity, structure and dynamics of the compounds [33][34][35][36][37][38][39][40][41][42][43][44].…”

The elastic and thermodynamic properties of antiperovskites: MCNi3

“…Tong et al [22] have indicated the presence of strong electron-electron correlations in GaCNi 3 through the specific heat measurements, whereas a weak ferromagnetism has been observed in AlCNi 3 [21]. ZnCNi 3 is a Pauli PM metal [14] and CdCNi 3 is a superconductor with T c = 3.4 K [24].…”

Atomistic simulation of dynamical and defect properties of multiferroic hexagonal YMnO3

“…Figure 1 gives the total and partial phonon densities of states for h-YMnO 3 , which span the spectral range from 0 to 75 meV. The phonon vibrations due to Y, Mn and O atoms show distinct difference with those from orthorhombic YMnO 3 [4]. Y1 and Y2 atoms contribute to low energy range (716 meV).…”

“…Raman and infrared spectra of h-YMnO 3 have been discussed by Iliev et al [2] and phonon modes were also assigned by Zaghrioui et al [3]. Nevertheless, some vibrational properties such as phonon density of state have not been reported and are still elusive compared with orthorhombic YMnO 3 [4].…”