Eur. Phys. J. D (2015) 69: 177
https://doi.org/10.1140/epjd/e2015-60186-4

Regular Article

Structural and mechanic properties of RFeO₃ with R = Y, Eu and La perovskites: a first-principles calculation

¹ Facultad de Ciencias, Universidad Nacional Autónoma de México, Apartado Postal 70-399, 04510 México, D.F., México
² Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, 04510 México, D.F., México
³ ESIME-Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana 1000, C.P. 04430, México, D.F., México

^a e-mail: mromero@ciencias.unam.mx

Received: 18 March 2015
Received in final form: 15 May 2015
Published online: 19 July 2015

Abstract

The structural and elastic properties of the RFeO₃ phases with R = Y, Eu, and La were investigated using first-principles plane-wave pseudopotential density functional theory with the generalized gradient approximation (GGA). The ground state properties (equilibrium cell constants) agree well with the reported experimental results. Our results showed an increase in the unit-cell volume (V) with the increase of ionic radii. We calculate a set of elastic parameters (bulk modulus B_VRH, shear modulus G_VRH, Young’s modulus E_VRH and Poisson’s ratio ν) in the framework of the Voigt-Reuss-Hill (VRH) approximation. The sound velocities (v_l, v_t) and Debye temperature (θ_D) were calculated using these elastic moduli. The calculated elastic constants were positives and satisfy the well-known Born criteria, indicating that the orthorhombic structure is stable. Finally, the ratio G_VRH/B_VRH suggests that the RFeO₃ phases are ductile in nature.