Elastic, electronic, thermal and magnetic investigations of PrX2 (X = Fe,Ru) superconductors materials

Abstract

The structural, elastic, electronic properties, thermal properties and magnetic hyperfine field and thermoelectric response of Laves phase PrFe2 and PrRu2 compounds are researched by using density functional theory via full-potential linear augmented plane waves (FP-LAPW) method within the local orbitals joining the generalized gradient approximation (GGA-PBESol) of exchange-correlation functional as applied in WIEN2k software package. Additionally, the semi-classical Boltzmann theory is utilized to investigate the stress behavior and superconductors applications on magnetic moments of each atom from 0 to 25 GPa for both materials are researched. The GGA-PBESol+U approximation is employed to address the f states of Pr atoms and d states of Fe and Ru atoms. The geometrical analysis of structural parameters is applied. The structural parameters calculated by two approximations are in a good agreement with other results. The calculated elastic constants, Young's modulus, shear modulus, Poisson's ratio, sound velocities and Debye temperature are investigated. The thermodynamic properties are calculated by a semi-harmonic Debye model in the pressure range, 0–25 GPa and temperature, 0–1000 K. The partial and total density of states (DOS) are investigated for PrFe2 and PrRu2 compounds. The partial DOS illustrates a hybridized strong at Fermi level. While, the hyperfine magnetic field is determined using two GGA-PBESol and GGA-PBESol+U approximations. Both PrFe2 and PrRu2 have superconducting critical temperatures; 550 K and 580 K, respectively. The comprehensive experimental characterization of PrRu2 is still absent in the literature and superconducting critical-temperature values are favorable with a similar experimental value; 530 K for PrFe2