New equiatomic quaternary Heusler compounds without transition metals KCaBX (X = S and Se): Robust half-metallicity and optical properties
Graphical abstract
Introduction
The rapid development of science and technology demands the processing of extremely large data volume with highest speed as possible to reduce the time consuming. In this regard, the traditional electronics have become obsolete and the spintronics have emerged as the next electronics generation. In this field, the electronic spin is employed as an additional degree of freedom to process and transport information [1,2]. In comparison with the traditional electronic devices, those based on the spintronics can store higher data volume, being capable of processing and transporting extremely faster information [3,4]. For the use in spintronics, the highly spin-polarized materials are desirable. In this regard, half-metallic materials with a complete spin-polarization have been suggested and widely investigated. One of the most exciting half-metallic materials class is the Heusler compounds family [5,6]. So far, most of investigations have treated materials which contain transition metals as constituents [[7], [8], [9], [10], [11], [12]]. Quaternaries compounds have been extensively investigated in both aspects of experiments and theories due to their promising practical applications [[13], [14], [15], [16], [17], [18], [19], [20], [21], [22]]. On the other hand, the half-metallic ferromagnetism has been found in many materials without transition metals [[23], [24], [25]]. Between the studied materials, there are found the equiatomic quaternary Heusler (EQH) compounds. For example, Du et al. [26] have predicted the half-metallicity with metallic spin-up and semiconductor spin-dn in the KCaCF and KCaCCl compounds. The total magnetic moment of 2 μB has been obtained which is originated predominantly from the C-2p state. The CsSrCZ (Z = P, As and Sb) compounds exhibit the half-metallic behavior with a total magnetic moment of 2 μB according to Bouabca et al. [27]. The perfect spin-polarization of the KCaNX (X = O, S and Se) compounds has been confirmed by Du et al. [28] within DFT calculations. In general, half-metallic materials without transition metals have considerably large spin-flip band gap than those containing transition metals, suggesting the robustness of the half-metallicity and magnetism under effect of working conditions.
Herein, two new EQH compounds without transition metals, namely, KCaBS and KCaBSe, are introduced. The study focuses on the structural, electronic, magnetic and optical properties of these EQH compounds. Despite the absence of transition metals, KCaBS and KCaBSe compounds exhibit important ferromagnetism, which is derived mainly from the B-p state spin-polarization. Simulations also assert that materials at hand are half-metallic with a perfect spin-polarization at the Fermi level showing metallic nature in the spin-up channel and semiconducting behavior in the spin-dn channel. Interestingly, the half-metallicity and magnetism are robust under strain effect. Wide absorption band with large absorption coefficient are obtained for the studied compounds. Results suggest that KCaBS and KCaBSe may be promising materials for applications in spintronic and optoelectronic devices. The rest of the paper is divided into three section: the FP-LAPW is briefly described in Section.2, in which main parameters such as cut-off energies, k-mesh size are also given. Results of the structural design, electronic structure, magnetic and optical properties of KCaBX compounds are presented and discussed in Section.3; Finally, the most relevant results are summarized in Section.4.
Section snippets
Computational details
First principles calculations based on the density functional theory (DFT) [29] are performed to carry out a detailed investigation on the structural, electronic, magnetic and optical properties of the EQH KCaBX (X = S and Se) compounds. In this work, the crystal is divided into two regions: non-overlapping spheres (muffin-tin) centered at each atom of the radius RMT and the interstitial region. Within atomic spheres, electron states are expanded in a linear combination of the radial functions
Structural properties
The crystal structure of EQH compounds is similar to that of the full-Heusler compound, showing the face-centered cubic structure ascribed to the F43 m space group (no. 216). In the unit cell, there are four formula units occupying four Wyckoff positions: 4a(0; 0; 0), 4b(0.5; 0.5; 0.5), 4c(0.25; 0.25; 0.25) and 4d(0.75; 0.75; 0.75). Consequently, there are three possible arrangements of constituent atoms (K, Ca, B, X) for the EQH KCaBX compounds. To be precise, they are the following: (4c, 4d,
Conclusions
In general, the structural, electronic, magnetic and optical properties of new EQH KCaBX (X = S and Se) compounds have been investigated with the use of the FP-LAPW method. KCaBS and KCaBSe alloys are promising materials for the spintronic and optoelectronic applications. In what follows the main results are summarized:
- •
The KCaBX alloys crystallize in the type I cubic structure belonging to the F43 m space group with ferromagnetic configuration.
- •
The formation energy and cohesive energy support
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgement
This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 103.01–2019.348.
References (43)
Spintronics: a contemporary review of emerging electronics devices, Engineering science and technology
Int. J.
(2016)- et al.
First-principle calculations of structural, electronic and magnetic investigations of Mn2RuGe1−xSnx quaternary Heusler alloys
Chin. J. Phys.
(2018) - et al.
Structural and magnetic properties of Co2CrAl Heusler alloys prepared by mechanical alloying
J. Magn. Magn Mater.
(2010) - et al.
Half-metallicity and anisotropy magnetoresistance properties of Heusler alloys Fe2Co1−xCrxSi
J. Magn. Magn Mater.
(2013) - et al.
Calculation of structural, optical and electronic properties of ZnS, ZnSe, MgS, MgSe and their quaternary alloy Mg1−xZnxSySe1−y
Mater. Sci. Eng., B
(2003) - et al.
Structural and electronic properties of zinc blende BxAl1−xNyP1−y quaternary alloys via first-principle calculations
Phys. B Condens. Matter
(2012) - et al.
First-principles prediction of the structural, elastic, thermodynamic, electronic and optical properties of Li4Sr3Ge2N6 quaternary nitride
J. Alloys Compd.
(2015) - et al.
Structural, elastic, electronic and optical properties of the quaternary nitridogallate LiCaGaN2: first-principles study
Mater. Sci. Semicond. Process.
(2015) - et al.
Structural, elastic, electronic and optical properties of the novel quaternary diamond-like semiconductors Cu2MgSiS4 and Cu2MgGeS4
Solid State Sci.
(2017) - et al.
Synthesis and characterization of Cu2CdSnS4 quaternary alloy nanostructures
Int. J. Electrochem. Sci
(2018)
Search for new d0 half-metallic materials: theoretical investigation on KCaC1−xSix (x= 0; 0.25; 0.5; 0.75 and 1) compounds
Chin. J. Phys.
Half-metallic property of the bulk and (001) surfaces of MNaCs (M= P, As) half-Heusler alloys: a density functional theory approach
Surf. Sci.
Half-metallic ferromagnetism in the full-Heusler compounds KCaX2 (X= C, N, and O)
Comput. Mater. Sci.
Half-metallic ferromagnetic features in d0 quaternary-Heusler compounds KCaCF and KCaCCl: a first-principles description
J. Magn. Magn Mater.
First-principles study of new series of quaternary Heusler alloys CsSrCZ (Z= Si, Ge, Sn, P, As, and Sb)
J. Magn. Magn Mater.
Half-metallic ferromagnetism in KCaNX (X= O, S, and Se) quaternary Heusler compounds: a first-principles study
Superlattice. Microst.
Solid state calculations using WIEN2k
Comput. Mater. Sci.
Structural, optoelectronic and thermoelectric properties of antiperovskite compounds Ae3PbS (Ae= Ca, Sr and Ba): a first principles study
Phys. Lett.
Half-metallicity and magnetism of quaternary Heusler compounds CoRuTiZ (Z= Si, Ge, and Sn)
J. Magn. Magn Mater.
Investigation on new equiatomic quaternary Heusler compound CoCrIrSi via FP-LAPW calculations
Chem. Phys.
Examining the half-metallicity and thermoelectric properties of new equiatomic quaternary Heusler compound CoVRhGe under pressure
Phys. B Condens. Matter
Cited by (9)
Structural configuration and phase stability in the quaternary Heusler compounds CoCrYSb (Y=Sc,Ti, V)
2022, Computational and Theoretical ChemistryCitation Excerpt :Some people then use elemental substitution, replacing one X element in a full Heusler alloy with a fourth different element to obtain a quaternary Heusler alloy with the chemical expression XX'YZ [29–34]. Since the quaternary Heusler alloy has an elemental ratio of 1:1:1:1, it is also known as equivalent quaternary Heusler (EQH) [35,36]. The research on Heusler alloys mainly focuses on the more common cubic phase, but some recent studies have found that the cubic phase of these ternary alloys may not be the most stable, and sometimes the tetragonal phase is more popular.
First-principles calculations to investigate electronic structure and transport properties of CrC monolayers: A new horizon for spintronic application
2021, Materials Science and Engineering: BCitation Excerpt :Graphene and graphene like systems [1–7] are widely studied with various modifications. Phosphorene, transition metal di-chacogenides, m-xenes, transition metal nitrides have triggered enormous attention due to their widespread applications based on recent demands in photovoltaics, nanoelectronics and nanodevices [8–31]. The rediscovery of ferromagnetism in single layered structure has sparkled the motivation to find new materials with intrinsic spin interactions [32–40].
Structural, electronic, magnetic and optical properties of CaO induced by oxygen incorporation effects: A first-principles study
2021, Physics Letters, Section A: General, Atomic and Solid State PhysicsCitation Excerpt :Doubtless that the absence of spin-up electronic state at the Fermi level vicinities generates the perfect 100% spin-polarization. Results suggest that the oxygen incorporation in the CaO compound may induce the half-metallicity with large spin-flip gaps [32,33], making possible the application in the spintronic devices provided that they can be used to supply highly polarized electrons [34–37]. In conclusion, the structural, electronic, magnetic, and optical properties of the oxygen-incorporated CaO systems have been systematically investigated through the first-principles calculations.
First-principles investigations of ZnO monolayers derived from zinc-blende and 5-5 phases for advanced thermoelectric applications
2021, Journal of Physics and Chemistry of SolidsCitation Excerpt :Therefore, the main focus of the ongoing research is to reduce thermal conductivity and improve the thermoelectric performance. The dimensionality reduction has been found to effectively reduce thermal conductivity and enhance the performance of thermoelectric materials [7–18]. For example, the room temperature zT value of SnSe has been upgraded to ~2.06 by modifying its structure into two dimensions [19].