Inverse-perovskite oxides with , Ge, Sn, Pb: Structural, elastic and thermal properties
Introduction
Inverse-perovskites of the general formula , where are alkaline-earth metals, are rare-earth metals, E are -group elements and are C, N or O, were frequently reported [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14]. These ternary compounds display a wide range of physical properties, from wide-gap insulators to ferroelectrics and superconductors, as well as wide range of structural instabilities. Physical properties of the inverse-perovskite nitrides and carbides have received much attention and have been the subject of many theoretical and experimental works in the last two decades. Particularly, the alkaline-earth metal nitrides of the group 15 elements (E = P, As, Sb, Bi), with the composition , show electrically insulating properties [15], [16], [17]. The crystalline structures cover the range of cubic inverse-perovskite-type at ambient conditions for and orthorhombic distortion variants in space group Pnma for [16], [17]. The compounds with the composition crystallize in the inverse hexagonal (2H) perovskite-type (BaNiO3-type) [15]. Additionally Mg-containing compounds were reported, which crystallize in the cubic inverse-perovskite-type structure [18].
Compared to the cubic inverse-perovskite nitrides and carbides, which have been intensively investigated, the inverse-perovskite oxides constitute a relatively unknown branch of the perovskite family. The family of inverse-perovskite oxides is still poorly studied and many of their properties are not explored. Remarkably, only few inverse-perovskite oxides of the rare-earth metals have been reported: La3InO [8], La3AlO,Ce3AlO [3] and [11], [12]. Alkaline-earth metal inverse-perovskite oxides are exclusively known containing group 14 elements and are semiconductors with the general formula [1], [2], [12], [13], [14]. The ideal cubic inverse-perovskite compounds were reported by Widera and Schäfer [1], [2] and by Röhr [13].
In the present work, we investigate the structural, elastic and thermodynamic properties of the ideal cubic inverse-perovskites: Ca3SiO,Ca3GeO,Ca3SnO and Ca3PbO, using the state of the art pseudo-potential plane-wave method (PP-PW), in the framework of the density functional theory (DFT) within two different approximations for the exchange–correlation functional. The paper is organized as follows: In Section 2, we briefly describe the computational method used in this study. The most relevant results obtained for the structural, elastic and thermal properties of Ca3EO compounds are presented and discussed in Section 3. Concluding remarks are given in Section 4.
Section snippets
Computational details
The calculations were carried out by means of the pseudo-potential plane-wave (PP-PW) method within the framework of the density functional theory (DFT), implemented in the CASTEP package [19]. Interactions of valence electrons with ion cores were treated using the Vanderbilt-type ultra-soft pseudo-potential [20]. The exchange–correlation energy was treated within both the generalized gradient approximation of Perdew, Burke and Ernzerhof (GGA–PBE) [21] and the local density approximation (LDA)
Structural properties
The calculated equilibrium lattice constants of Ca3SiO, Ca3GeO, Ca3SnO and Ca3PbO are presented in Table 1, along with the available experimental findings. Better theoretical results are obtained with the GGA. The computed lattice constants using the GGA deviate from the measured ones within 0.42%, 0.16%, 0.17% and 0.57% for Ca3SiO,Ca3GeO,Ca3SnO and Ca3PbO, respectively. The bulk modulus and its pressure derivative were calculated by fitting the pressure–volume data to a third-order
Conclusion
To summarize, for the first time, we have performed first-principles calculations on the Ca3SiO,Ca3GeO,Ca3SnO and Ca3PbO compounds in cubic inverse-perovskite-type phase. The structural and elastic properties have been calculated by using a pseudo-potential plane-wave approach based on the density functional theory, within the GGA and LDA. The optimized lattice parameters agree very well with the experimental findings; validating the used method. The mechanical behavior was investigated and
References (56)
- et al.
Mater. Res. Bull.
(1980) - et al.
J. Less-Common Met.
(1981) - et al.
Solid State Sci.
(2003) J. Less-Common Met.
(1985)- et al.
J. Alloys Compd.
(1995) - et al.
J. Solid State Chem.
(1992) - et al.
J. Solid State Chem.
(1992) Phys. B: Condens. Matter
(2008)- et al.
Comput. Mater. Sci.
(2007) - et al.
J. Phys. Chem. Solids
(2007)
J. Mech. Phys. Solids
J. Alloys Compd.
J. Phys. Chem. Solids
Z. Kristallogr.
Z. Naturforsch. B
Monatsh. Chem.
Z. Anorg. Allg. Chem.
Z. Anorg. Allg. Chem.
Z. Anorg. Allg. Chem.
Z. Kristallogr.
Z. Anorg. Allg. Chem.
Z. Anorg. Allg. Chem.
Solid State Commun.
J. Phys.: Condens. Matter
Phys. Rev. B
Phys. Rev. Lett.
Phys. Rev. Lett.
Cited by (11)
Spin-orbit coupling effect on the optoelectronic and thermoelectric properties of the perovskites A<inf>3</inf>SnO (A = Ca, Sr and Ba)
2021, Materials Science in Semiconductor ProcessingCitation Excerpt :Nuss et al. [2] reported that inverse perovskites crystallizes in ideal cubic structure at room temperature while distorted at higher temperature. Calcium based perovskites have been extensively investigated [15–19]. Strontium based inverse perovskite (Sr3SnO) was investigated in different studies [1,11,20–22] and their physical properties were reported.
An Ab Initio study of electronic, mechanical, thermoelectric and vibrational properties of Dirac Semimetals Ca<inf>3</inf>PbO and Ca<inf>3</inf>SnO
2021, Materials Today CommunicationsCitation Excerpt :In order to evaluate the equilibrium lattice constant (a0), the bulk modulus (B) and pressure derivative of bulk modulus (B’) at P = 0 GPa and T = 0 K, the energy-volume data is fitted to third orders Birch–Murnaghan equation of state [34]. The obtained convergent value of lattice cell parameter is 4.724 Å for Ca3PbO and 4.679 Å for Ca3SnO, which is consistent with the experimental [16] and theoretical [35] available results as tabulated in Table 1. The value of lattice constant (a0) of Ca3SnO < Ca3PbO, Sn being smaller in size than Pb.
Structural, electronic, optical and thermoelectric investigations of antiperovskites A<inf>3</inf>SnO (A = Ca, Sr, Ba) using density functional theory
2018, Solid State CommunicationsCitation Excerpt :Widera and his co-workers [25] synthesized alkaline earth stannate for the very first time and reported that their lattice parameter is around 4 Å, which is largest among the known anti-perovskites [26]. The anti-perovskites stannates of carbide and nitride have been extensively studied but the family of oxides such as Ca3SnO [27], Mn3SnO [28] and Ba3SnO [29,30] have been less investigated. The pressure dependence of elastic co-efficient for Ca3EO (E=Si, Ge, Sn) has depicted that pough's ratio (B/G) computed for these compounds illustrate brittle natures [27].
A theoretical study for thorium monocarbide (ThC)
2012, Journal of Nuclear MaterialsProbing thermoelectric properties of high potential Ca<inf>3</inf>PbO: An Ab Initio Study
2021, IOP Conference Series: Materials Science and EngineeringFirst principle study of structural and electronic properties of cubic inverse perovskite Ca<inf>3</inf>PbO
2020, AIP Conference Proceedings