Electronic and elastic properties of non-oxide anti-perovskites from first principles: SuperconductingCdCNi3in comparison with magneticIn

Abstract

Full-potential linearized augmented plane-wave method with the generalized gradient approximation for the exchange-correlation potential has been applied for the comparative study of structural, elastic, and electronic properties of the synthesized non-oxide anti-perovskites: superconducting CdCNi 3 and magnetic InCNi 3 . The optimized lattice parameters, independent elastic constants ͑C 11 , C 12 , and C 44 ͒, bulk modules B, compressibility ␤, shear modules G, and tetragonal shear modules GЈ are evaluated. The numerical estimates of the elastic parameters of the polycrystalline InCNi 3 and CdCNi 3 ceramics are performed. The band structures, total and site-projected l-decomposed densities of states, the shapes of the Fermi surfaces, the Sommerfeld coefficients, and the molar Pauli paramagnetic susceptibility for these anti-perovskites are obtained and analyzed in comparison with the available theoretical and experimental data. From our calculations, the stoichiometric CdCNi 3 and InCN 3 are very much alike in both structural and elastic properties but differ in electronic properties. For InCNi 3 , the defect-induced magnetism associated with the indium vacancies or Ni atoms substituting for In was found.

Elastic and Thermodynamic Properties of Anti-Perovskite Type Superconductor MCNi3(M = Zn, Cd)

“…[8]; i Ref. [24] For ZnCNi 3 , our lattice constant a 0 from GGA and LDA approaches are close to those given by Sieberer et al and Joseph et al [4,5]. Their experimental data have the difference of 0.11 Å.…”

The elastic and thermodynamic properties of antiperovskites: MCNi3

“…(C 11 − C 12 ) > 0, (C 11 + 2C 12 ) > 0, and C 44 > 0. The bulk modulus calculated from elastic constants for these materials is very close to other available data [42][43][44][45]. The bulk moduli of these crystals increase in the sequence AgCNi 3 < ZrCNi 3 < MgCNi 3 < ZnCNi 3 < CdCNi 3 < TcCNi 3 .…”

“…(4)-(10) and the calculated values are listed in Table 3, together with the available experimental [15] and other theoretical [42,43,16,44,45] data.…”

“…The values of the input data (r 0 , B) [1,42,43] (listed in Table 1) have been used for the evaluation of the model parameters (b 1 , 1 ) and (b 2 , 2 ), corresponding to the ionic bond M-Ni and Ni-C distances (r 0 ) at different temperatures. The vdW coefficients are evaluated from the SKV [37] method for the present compounds.…”

Electronic structure of new oxygen-free 38-K superconductor Ba1−x K x Fe2As2 in comparison with BaFe2As2 from the first principles

“…these materials should be within the weak coupling limit. For comparison, for other superconducting oxygen-free species with magnetic ions, such as ACNi 3 antiperovskites, the available experimental and theoretical estimations of λ varies from 1.4 to 0.66, see [30].…”