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Both spin gapless semiconductors (SGSs) and nodal ring states (NRSs) have aroused great scientific interest in recent years due to their unique electronic properties and high application potential. However, since their advent, all SGSs and NRSs have been predicted in independent materials. In this work, we proposed a novel type of material, nodal ring spin gapless semiconductor (NRSGS), which combines both states of the SGSs and NRSs. The synthesized material Mg2VO4 is selected as a potential candidate. Detailed band structure analysis reveals that there are gapless crossings in the spin-up direction, which are from multiple topological nodal rings located exactly at the Fermi energy level. Mg2VO4 combines the advantages inherited from both NRSs and SGSs in terms of the innumerable gapless points along multiple nodal rings with all linear dispersions and direct contacts. In addition, Mg2VO4 also shows strong robustness against both the spin orbit coupling effect and strain conditions. Therefore, for the first time, we propose the concept of an NRSGS, and the first such material candidate Mg2VO4 can immediately advance corresponding experimental measurements and even facilitate real applications.

2020 Elsevier B.V. Very recently, a novel Dirac half-metal has been investigated in the perovskite-type lanthanum manganite (LaMnO3) by Ma et al. [1] and the half metallicity with 100% spin polarization is discovered. More remarkably, multiple linear Dirac crossings are observed around the Fermi energy level in the spin-up direction. Inspired by this work, another perovskite-type material YbBO3, which has been synthesized before, is investigated by first principles calculation. Results confirm the presence of half metallicity in this material with also multiple Dirac-like linear and parabolic band crossings around the Fermi level. The estimated Curie temperature is 469.4 K and the mechanic and dynamic stabilities have been verified. Besides, the elastic anisotropy is revealed with the directional dependent Young's modulus and shear modulus, together with the acoustic wave properties. The effect of the uniform strain, electron doping and spin-orbital coupling on the electronic structures have been also accessed. In particular, nearly spin-gapless semiconducting behavior with linear or parabolic energy dispersions is obtained by electron doping. Moreover, several thermodynamic properties have been examined under temperature from 0 to 500 K and pressure from 0 to 5 GPa. In combination, we expect YbBO3 can attract more research attention and even facilitate the spintronic application.

Both spin gapless semiconductors (SGSs) and nodal ring states (NRSs) have aroused great scientific interest in recent years due to their unique electronic properties and high application potential. However, since their advent, all SGSs and NRSs have been predicted in independent materials. In this work, we proposed a novel type of material, nodal ring spin gapless semiconductor (NRSGS), which combines both states of the SGSs and NRSs. The synthesized material Mg2VO4 is selected as a potential candidate. Detailed band structure analysis reveals that there are gapless crossings in the spin-up direction, which are from multiple topological nodal rings located exactly at the Fermi energy level. Mg2VO4 combines the advantages inherited from both NRSs and SGSs in terms of the innumerable gapless points along multiple nodal rings with all linear dispersions and direct contacts. In addition, Mg2VO4 also shows strong robustness against both the spin orbit coupling effect and strain conditions. Therefore, for the first time, we propose the concept of an NRSGS, and the first such material candidate Mg2VO4 can immediately advance corresponding experimental measurements and even facilitate real applications.

2020 Elsevier B.V. Very recently, a novel Dirac half-metal has been investigated in the perovskite-type lanthanum manganite (LaMnO3) by Ma et al. [1] and the half metallicity with 100% spin polarization is discovered. More remarkably, multiple linear Dirac crossings are observed around the Fermi energy level in the spin-up direction. Inspired by this work, another perovskite-type material YbBO3, which has been synthesized before, is investigated by first principles calculation. Results confirm the presence of half metallicity in this material with also multiple Dirac-like linear and parabolic band crossings around the Fermi level. The estimated Curie temperature is 469.4 K and the mechanic and dynamic stabilities have been verified. Besides, the elastic anisotropy is revealed with the directional dependent Young's modulus and shear modulus, together with the acoustic wave properties. The effect of the uniform strain, electron doping and spin-orbital coupling on the electronic structures have been also accessed. In particular, nearly spin-gapless semiconducting behavior with linear or parabolic energy dispersions is obtained by electron doping. Moreover, several thermodynamic properties have been examined under temperature from 0 to 500 K and pressure from 0 to 5 GPa. In combination, we expect YbBO3 can attract more research attention and even facilitate the spintronic application.

Both spin gapless semiconductors (SGSs) and nodal ring states (NRSs) have aroused great scientific interest in recent years due to their unique electronic properties and high application potential. However, since their advent, all SGSs and NRSs have been predicted in independent materials. In this work, we proposed a novel type of material, nodal ring spin gapless semiconductor (NRSGS), which combines both states of the SGSs and NRSs. The synthesized material Mg2VO4 is selected as a potential candidate. Detailed band structure analysis reveals that there are gapless crossings in the spin-up direction, which are from multiple topological nodal rings located exactly at the Fermi energy level. Mg2VO4 combines the advantages inherited from both NRSs and SGSs in terms of the innumerable gapless points along multiple nodal rings with all linear dispersions and direct contacts. In addition, Mg2VO4 also shows strong robustness against both the spin orbit coupling effect and strain conditions. Therefore, for the first time, we propose the concept of an NRSGS, and the first such material candidate Mg2VO4 can immediately advance corresponding experimental measurements and even facilitate real applications.

Both spin gapless semiconductors (SGSs) and nodal ring states (NRSs) have aroused great scientific interest in recent years due to their unique electronic properties and high application potential. However, since their advent, all SGSs and NRSs have been predicted in independent materials. In this work, we proposed a novel type of material, nodal ring spin gapless semiconductor (NRSGS), which combines both states of the SGSs and NRSs. The synthesized material Mg2VO4 is selected as a potential candidate. Detailed band structure analysis reveals that there are gapless crossings in the spin-up direction, which are from multiple topological nodal rings located exactly at the Fermi energy level. Mg2VO4 combines the advantages inherited from both NRSs and SGSs in terms of the innumerable gapless points along multiple nodal rings with all linear dispersions and direct contacts. In addition, Mg2VO4 also shows strong robustness against both the spin orbit coupling effect and strain conditions. Therefore, for the first time, we propose the concept of an NRSGS, and the first such material candidate Mg2VO4 can immediately advance corresponding experimental measurements and even facilitate real applications.

2020 Elsevier B.V. Very recently, a novel Dirac half-metal has been investigated in the perovskite-type lanthanum manganite (LaMnO3) by Ma et al. [1] and the half metallicity with 100% spin polarization is discovered. More remarkably, multiple linear Dirac crossings are observed around the Fermi energy level in the spin-up direction. Inspired by this work, another perovskite-type material YbBO3, which has been synthesized before, is investigated by first principles calculation. Results confirm the presence of half metallicity in this material with also multiple Dirac-like linear and parabolic band crossings around the Fermi level. The estimated Curie temperature is 469.4 K and the mechanic and dynamic stabilities have been verified. Besides, the elastic anisotropy is revealed with the directional dependent Young's modulus and shear modulus, together with the acoustic wave properties. The effect of the uniform strain, electron doping and spin-orbital coupling on the electronic structures have been also accessed. In particular, nearly spin-gapless semiconducting behavior with linear or parabolic energy dispersions is obtained by electron doping. Moreover, several thermodynamic properties have been examined under temperature from 0 to 500 K and pressure from 0 to 5 GPa. In combination, we expect YbBO3 can attract more research attention and even facilitate the spintronic application.

2020 Elsevier B.V. Very recently, a novel Dirac half-metal has been investigated in the perovskite-type lanthanum manganite (LaMnO3) by Ma et al. [1] and the half metallicity with 100% spin polarization is discovered. More remarkably, multiple linear Dirac crossings are observed around the Fermi energy level in the spin-up direction. Inspired by this work, another perovskite-type material YbBO3, which has been synthesized before, is investigated by first principles calculation. Results confirm the presence of half metallicity in this material with also multiple Dirac-like linear and parabolic band crossings around the Fermi level. The estimated Curie temperature is 469.4 K and the mechanic and dynamic stabilities have been verified. Besides, the elastic anisotropy is revealed with the directional dependent Young's modulus and shear modulus, together with the acoustic wave properties. The effect of the uniform strain, electron doping and spin-orbital coupling on the electronic structures have been also accessed. In particular, nearly spin-gapless semiconducting behavior with linear or parabolic energy dispersions is obtained by electron doping. Moreover, several thermodynamic properties have been examined under temperature from 0 to 500 K and pressure from 0 to 5 GPa. In combination, we expect YbBO3 can attract more research attention and even facilitate the spintronic application.

In the past three years, Dirac half-metals (DHMs) have attracted considerable attention and become a high-profile topic in spintronics becuase of their excellent physical properties such as 100% spin polarization and massless Dirac fermions. Two-dimensional DHMs proposed recently have not yet been experimentally synthesized and thus remain theoretical. As a result, their characteristics cannot be experimentally confirmed. In addition, many theoretically predicted Dirac materials have only a single cone, resulting in a nonlinear electromagnetic response with insufficient intensity and inadequate transport carrier efficiency near the Fermi level. Therefore, after several attempts, we have focused on a novel class of DHMs with multiple Dirac crossings to address the above limitations. In particular, we direct our attention to three-dimensional bulk materials. In this study, the discovery via first principles of an experimentally synthesized DHM LaNiO3 with many Dirac cones and complete spin polarization near the Fermi level is reported. It is also shown that the crystal structures of these materials are strongly correlated with their physical properties. The results indicate that many rhombohedral materials with the general formula LnNiO3 (Ln = La, Ce, Nd, Pm, Gd, Tb, Dy, Ho, Er, Lu) in the space group R 3 c are potential DHMs with multiple Dirac cones.

Very recently, two R3−c Dirac half-metal materials, LaMnO3 and MnF3, were found and investigated by Du et al. via first principles. They stated that these types of materials with half-metallic band structures and multiple linear band dispersions might exhibit excellent 100% spin polarization and ultrafast electron transport. However, the application of MnF3 material in the field of spintronics is limited owing to its low Curie temperature (Tc). In this work, we proposed a new half-metal material-MnBO3. This material satisfies two demands at the same time-it is a half-metal with a high Tc, and it has multiple nearly linear band crossings. The effects of the uniform strain, vacancies, spin-orbit coupling, as well as hole and electron doping on its electronic structures have been discussed in detail. Furthermore, to better study its specific behaviors under extreme conditions, such as high temperature or pressure, we also investigated the thermodynamic properties of MnBO3 through the quasi-harmonic Debye model. Finally, its thermal stability at room temperature has been proved in this article by means of ab initio molecular dynamics (AIMD) simulations. We hope that MnBO3 can attract more attention for R3−c-type half-metallic materials with linear band crossings and a high Curie temperature in experimental and theoretical areas.

In recent years, the search for new Dirac half-metallic materials has been one of the hotspots in the field of spintronics because they have very good physical properties, such as massless Dirac fermions and full spin polarization. In this study, using density function theory combined with the quasi-harmonic Debye model, we show that perovskite-type dysprosium manganite is a novel half metal with multiple Dirac cones. A detailed study of the electronic, magnetic, and thermodynamic properties of DyMnO3 was carried out. Furthermore, the effects of uniform strain, the on-site Coulomb interaction U, spin-orbit coupling, and hole and electron doping on the multiple Dirac cones and full spin polarization were investigated. We should point out that such a spin-polarized Dirac material is rare among perovskite-type compounds. Hence, we hope that, through this work, this kind of material will receive more extensive attention in future studies.

Very recently, experimentally synthesized R3c phase LaCuO3 was studied by Zhang, Jiao, Kou, Liao & Du [J. Mater. Chem. C (2018), 6, 6132-6137], and they found that this material exhibits multiple Dirac cones in its non-spin-polarized electronic structure. Motivated by this study, the focus here is on a new R3c phase material, AgCuF3, which has a combination of multiple Dirac cones and 100% spin polarization properties. Compared to the non-spin-polarized system LaCuO3, the spin-polarized Dirac behavior in AgCuF3 is intrinsic. The effects of on-site Coulomb interaction, uniform strain and spin-orbit coupling were added to examine the stability of its multiple Dirac cones and half-metallic behavior. Moreover, the thermodynamic properties under different temperatures and pressures were investigated, including the normalized volume, thermal volume expansion coefficient, heat capacity at constant volume and Debye temperature. The thermal stability and the phase stability of this material were also studied via ab initio molecular dynamic simulations and the formation energy of the material, respectively.

In this work, a series of all-d-metal Heusler alloys, X 2 - x Mn 1 + x V (X = Pd, Ni, Pt, Ag, Au, Ir, Co; x; = 1, 0), were predicted by first principles. The series can be roughly divided into two categories: XMn 2 V (Mn-rich type) and X 2 MnV (Mn-poor type). Using optimized structural analysis, it is shown that the ground state of these all-d-metal Heusler alloys does not fully meet the site-preference rule for classic full-Heusler alloys. All the Mn-rich type alloys tend to form the L2 1 structure, where the two Mn atoms prefer to occupy the A (0, 0, 0) and C (0.5, 0.5, 0.5) Wyckoff sites, whereas for the Mn-poor-type alloys, some are stable with XA structures and some are not. The c/a ratio was also changed while maintaining the volume the same as in the cubic state to investigate the possible tetragonal transformation of these alloys. The Mn-rich Heusler alloys have strong cubic resistance; however, all the Mn-poor alloys prefer to have a tetragonal state instead of a cubic phase through tetragonal transformations. The origin of the tetragonal state and the competition between the cubic and tetragonal phases in Mn-poor alloys are discussed in detail. Results show that broader and shallower density-of-states structures at or in the vicinity of the Fermi level lower the total energy and stabilize the tetragonal phases of X 2 MnV (X = Pd, Ni, Pt, Ag, Au, Ir, Co). Furthermore, the lack of virtual frequency in the phonon spectra confirms the stability of the tetragonal states of these Mn-poor all-d-metal Heusler alloys. This work provides relevant experimental guidance in the search for possible martensitic Heusler alloys in all-d-metal materials with less Mn and new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.

In the past three years, Dirac half-metals (DHMs) have attracted considerable attention and become a high-profile topic in spintronics becuase of their excellent physical properties such as 100% spin polarization and massless Dirac fermions. Two-dimensional DHMs proposed recently have not yet been experimentally synthesized and thus remain theoretical. As a result, their characteristics cannot be experimentally confirmed. In addition, many theoretically predicted Dirac materials have only a single cone, resulting in a nonlinear electromagnetic response with insufficient intensity and inadequate transport carrier efficiency near the Fermi level. Therefore, after several attempts, we have focused on a novel class of DHMs with multiple Dirac crossings to address the above limitations. In particular, we direct our attention to three-dimensional bulk materials. In this study, the discovery via first principles of an experimentally synthesized DHM LaNiO3 with many Dirac cones and complete spin polarization near the Fermi level is reported. It is also shown that the crystal structures of these materials are strongly correlated with their physical properties. The results indicate that many rhombohedral materials with the general formula LnNiO3 (Ln = La, Ce, Nd, Pm, Gd, Tb, Dy, Ho, Er, Lu) in the space group R 3 c are potential DHMs with multiple Dirac cones.

Very recently, two R3−c Dirac half-metal materials, LaMnO3 and MnF3, were found and investigated by Du et al. via first principles. They stated that these types of materials with half-metallic band structures and multiple linear band dispersions might exhibit excellent 100% spin polarization and ultrafast electron transport. However, the application of MnF3 material in the field of spintronics is limited owing to its low Curie temperature (Tc). In this work, we proposed a new half-metal material-MnBO3. This material satisfies two demands at the same time-it is a half-metal with a high Tc, and it has multiple nearly linear band crossings. The effects of the uniform strain, vacancies, spin-orbit coupling, as well as hole and electron doping on its electronic structures have been discussed in detail. Furthermore, to better study its specific behaviors under extreme conditions, such as high temperature or pressure, we also investigated the thermodynamic properties of MnBO3 through the quasi-harmonic Debye model. Finally, its thermal stability at room temperature has been proved in this article by means of ab initio molecular dynamics (AIMD) simulations. We hope that MnBO3 can attract more attention for R3−c-type half-metallic materials with linear band crossings and a high Curie temperature in experimental and theoretical areas.

Very recently, experimentally synthesized R3c phase LaCuO3 was studied by Zhang, Jiao, Kou, Liao & Du [J. Mater. Chem. C (2018), 6, 6132-6137], and they found that this material exhibits multiple Dirac cones in its non-spin-polarized electronic structure. Motivated by this study, the focus here is on a new R3c phase material, AgCuF3, which has a combination of multiple Dirac cones and 100% spin polarization properties. Compared to the non-spin-polarized system LaCuO3, the spin-polarized Dirac behavior in AgCuF3 is intrinsic. The effects of on-site Coulomb interaction, uniform strain and spin-orbit coupling were added to examine the stability of its multiple Dirac cones and half-metallic behavior. Moreover, the thermodynamic properties under different temperatures and pressures were investigated, including the normalized volume, thermal volume expansion coefficient, heat capacity at constant volume and Debye temperature. The thermal stability and the phase stability of this material were also studied via ab initio molecular dynamic simulations and the formation energy of the material, respectively.

In recent years, the search for new Dirac half-metallic materials has been one of the hotspots in the field of spintronics because they have very good physical properties, such as massless Dirac fermions and full spin polarization. In this study, using density function theory combined with the quasi-harmonic Debye model, we show that perovskite-type dysprosium manganite is a novel half metal with multiple Dirac cones. A detailed study of the electronic, magnetic, and thermodynamic properties of DyMnO3 was carried out. Furthermore, the effects of uniform strain, the on-site Coulomb interaction U, spin-orbit coupling, and hole and electron doping on the multiple Dirac cones and full spin polarization were investigated. We should point out that such a spin-polarized Dirac material is rare among perovskite-type compounds. Hence, we hope that, through this work, this kind of material will receive more extensive attention in future studies.

In this work, a series of all-d-metal Heusler alloys, X 2 - x Mn 1 + x V (X = Pd, Ni, Pt, Ag, Au, Ir, Co; x; = 1, 0), were predicted by first principles. The series can be roughly divided into two categories: XMn 2 V (Mn-rich type) and X 2 MnV (Mn-poor type). Using optimized structural analysis, it is shown that the ground state of these all-d-metal Heusler alloys does not fully meet the site-preference rule for classic full-Heusler alloys. All the Mn-rich type alloys tend to form the L2 1 structure, where the two Mn atoms prefer to occupy the A (0, 0, 0) and C (0.5, 0.5, 0.5) Wyckoff sites, whereas for the Mn-poor-type alloys, some are stable with XA structures and some are not. The c/a ratio was also changed while maintaining the volume the same as in the cubic state to investigate the possible tetragonal transformation of these alloys. The Mn-rich Heusler alloys have strong cubic resistance; however, all the Mn-poor alloys prefer to have a tetragonal state instead of a cubic phase through tetragonal transformations. The origin of the tetragonal state and the competition between the cubic and tetragonal phases in Mn-poor alloys are discussed in detail. Results show that broader and shallower density-of-states structures at or in the vicinity of the Fermi level lower the total energy and stabilize the tetragonal phases of X 2 MnV (X = Pd, Ni, Pt, Ag, Au, Ir, Co). Furthermore, the lack of virtual frequency in the phonon spectra confirms the stability of the tetragonal states of these Mn-poor all-d-metal Heusler alloys. This work provides relevant experimental guidance in the search for possible martensitic Heusler alloys in all-d-metal materials with less Mn and new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.

In the past three years, Dirac half-metals (DHMs) have attracted considerable attention and become a high-profile topic in spintronics becuase of their excellent physical properties such as 100% spin polarization and massless Dirac fermions. Two-dimensional DHMs proposed recently have not yet been experimentally synthesized and thus remain theoretical. As a result, their characteristics cannot be experimentally confirmed. In addition, many theoretically predicted Dirac materials have only a single cone, resulting in a nonlinear electromagnetic response with insufficient intensity and inadequate transport carrier efficiency near the Fermi level. Therefore, after several attempts, we have focused on a novel class of DHMs with multiple Dirac crossings to address the above limitations. In particular, we direct our attention to three-dimensional bulk materials. In this study, the discovery via first principles of an experimentally synthesized DHM LaNiO3 with many Dirac cones and complete spin polarization near the Fermi level is reported. It is also shown that the crystal structures of these materials are strongly correlated with their physical properties. The results indicate that many rhombohedral materials with the general formula LnNiO3 (Ln = La, Ce, Nd, Pm, Gd, Tb, Dy, Ho, Er, Lu) in the space group R 3 c are potential DHMs with multiple Dirac cones.

In the past three years, Dirac half-metals (DHMs) have attracted considerable attention and become a high-profile topic in spintronics becuase of their excellent physical properties such as 100% spin polarization and massless Dirac fermions. Two-dimensional DHMs proposed recently have not yet been experimentally synthesized and thus remain theoretical. As a result, their characteristics cannot be experimentally confirmed. In addition, many theoretically predicted Dirac materials have only a single cone, resulting in a nonlinear electromagnetic response with insufficient intensity and inadequate transport carrier efficiency near the Fermi level. Therefore, after several attempts, we have focused on a novel class of DHMs with multiple Dirac crossings to address the above limitations. In particular, we direct our attention to three-dimensional bulk materials. In this study, the discovery via first principles of an experimentally synthesized DHM LaNiO3 with many Dirac cones and complete spin polarization near the Fermi level is reported. It is also shown that the crystal structures of these materials are strongly correlated with their physical properties. The results indicate that many rhombohedral materials with the general formula LnNiO3 (Ln = La, Ce, Nd, Pm, Gd, Tb, Dy, Ho, Er, Lu) in the space group R 3 c are potential DHMs with multiple Dirac cones.

Very recently, two R3−c Dirac half-metal materials, LaMnO3 and MnF3, were found and investigated by Du et al. via first principles. They stated that these types of materials with half-metallic band structures and multiple linear band dispersions might exhibit excellent 100% spin polarization and ultrafast electron transport. However, the application of MnF3 material in the field of spintronics is limited owing to its low Curie temperature (Tc). In this work, we proposed a new half-metal material-MnBO3. This material satisfies two demands at the same time-it is a half-metal with a high Tc, and it has multiple nearly linear band crossings. The effects of the uniform strain, vacancies, spin-orbit coupling, as well as hole and electron doping on its electronic structures have been discussed in detail. Furthermore, to better study its specific behaviors under extreme conditions, such as high temperature or pressure, we also investigated the thermodynamic properties of MnBO3 through the quasi-harmonic Debye model. Finally, its thermal stability at room temperature has been proved in this article by means of ab initio molecular dynamics (AIMD) simulations. We hope that MnBO3 can attract more attention for R3−c-type half-metallic materials with linear band crossings and a high Curie temperature in experimental and theoretical areas.

In this work, a series of all-d-metal Heusler alloys, X 2 - x Mn 1 + x V (X = Pd, Ni, Pt, Ag, Au, Ir, Co; x; = 1, 0), were predicted by first principles. The series can be roughly divided into two categories: XMn 2 V (Mn-rich type) and X 2 MnV (Mn-poor type). Using optimized structural analysis, it is shown that the ground state of these all-d-metal Heusler alloys does not fully meet the site-preference rule for classic full-Heusler alloys. All the Mn-rich type alloys tend to form the L2 1 structure, where the two Mn atoms prefer to occupy the A (0, 0, 0) and C (0.5, 0.5, 0.5) Wyckoff sites, whereas for the Mn-poor-type alloys, some are stable with XA structures and some are not. The c/a ratio was also changed while maintaining the volume the same as in the cubic state to investigate the possible tetragonal transformation of these alloys. The Mn-rich Heusler alloys have strong cubic resistance; however, all the Mn-poor alloys prefer to have a tetragonal state instead of a cubic phase through tetragonal transformations. The origin of the tetragonal state and the competition between the cubic and tetragonal phases in Mn-poor alloys are discussed in detail. Results show that broader and shallower density-of-states structures at or in the vicinity of the Fermi level lower the total energy and stabilize the tetragonal phases of X 2 MnV (X = Pd, Ni, Pt, Ag, Au, Ir, Co). Furthermore, the lack of virtual frequency in the phonon spectra confirms the stability of the tetragonal states of these Mn-poor all-d-metal Heusler alloys. This work provides relevant experimental guidance in the search for possible martensitic Heusler alloys in all-d-metal materials with less Mn and new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.

Very recently, experimentally synthesized R3c phase LaCuO3 was studied by Zhang, Jiao, Kou, Liao & Du [J. Mater. Chem. C (2018), 6, 6132-6137], and they found that this material exhibits multiple Dirac cones in its non-spin-polarized electronic structure. Motivated by this study, the focus here is on a new R3c phase material, AgCuF3, which has a combination of multiple Dirac cones and 100% spin polarization properties. Compared to the non-spin-polarized system LaCuO3, the spin-polarized Dirac behavior in AgCuF3 is intrinsic. The effects of on-site Coulomb interaction, uniform strain and spin-orbit coupling were added to examine the stability of its multiple Dirac cones and half-metallic behavior. Moreover, the thermodynamic properties under different temperatures and pressures were investigated, including the normalized volume, thermal volume expansion coefficient, heat capacity at constant volume and Debye temperature. The thermal stability and the phase stability of this material were also studied via ab initio molecular dynamic simulations and the formation energy of the material, respectively.

In recent years, the search for new Dirac half-metallic materials has been one of the hotspots in the field of spintronics because they have very good physical properties, such as massless Dirac fermions and full spin polarization. In this study, using density function theory combined with the quasi-harmonic Debye model, we show that perovskite-type dysprosium manganite is a novel half metal with multiple Dirac cones. A detailed study of the electronic, magnetic, and thermodynamic properties of DyMnO3 was carried out. Furthermore, the effects of uniform strain, the on-site Coulomb interaction U, spin-orbit coupling, and hole and electron doping on the multiple Dirac cones and full spin polarization were investigated. We should point out that such a spin-polarized Dirac material is rare among perovskite-type compounds. Hence, we hope that, through this work, this kind of material will receive more extensive attention in future studies.

Spin-gapless semiconductors are considered as promising candidates for spintronic and magnetoelectronic materials. Enormous efforts have been devoted to search for materials in this regard. Recently, a new diamond-like quaternary semiconductor CuMn2InSe4 has been successfully synthesized by experiment and also demonstrated as spin-gapless semiconductor in theory. In this work, we report a theoretical study on the electronic, magnetic and thermodynamic properties of the CuMn2InSe4 under strain conditions by employing the first-principles calculations and quasi-harmonic Debye model. Under uniform strain, the spin-gapless semiconducting nature can only be maintained from 0% to 5% at the stretching side yet immediately destroyed at the compressing side. Although the magnetic moments of all atoms vary continuously with uniform strain, the total magnetic moment shows a good stability against uniform stretching up to 5%. The effect of the tetragonal distortion has also been studied in terms of strains in lattice a and c separately. Results show that strain in a has an important impact and induces larger variation on both the electronic and magnetic properties than in c. CuMn2InSe4 easily loses its spin-gapless semiconducting feature with the variation of strain in a but it can be maintained considerably better by strain in c. In particular, this spin-gapless behavior preserves through the whole studied range of strain in c from −5% to +5% at 100% a. While, the magnetic moments of all atoms under tetragonal distortion show the same variation tendencies under strain in a or c and the changing rate is a slightly larger with strain in a. Additionally, the thermodynamic properties of CuMn2InSe4 are predicted through the quasi-harmonic Debye model. The variation of bulk modulus, lattice constant, heat capacity, thermal expansion coefficient, Grüneisen constant and Debye temperature with pressure and temperature are successfully obtained. To the best of our knowledge, neither exp

Very recently, two R3−c Dirac half-metal materials, LaMnO3 and MnF3, were found and investigated by Du et al. via first principles. They stated that these types of materials with half-metallic band structures and multiple linear band dispersions might exhibit excellent 100% spin polarization and ultrafast electron transport. However, the application of MnF3 material in the field of spintronics is limited owing to its low Curie temperature (Tc). In this work, we proposed a new half-metal material-MnBO3. This material satisfies two demands at the same time-it is a half-metal with a high Tc, and it has multiple nearly linear band crossings. The effects of the uniform strain, vacancies, spin-orbit coupling, as well as hole and electron doping on its electronic structures have been discussed in detail. Furthermore, to better study its specific behaviors under extreme conditions, such as high temperature or pressure, we also investigated the thermodynamic properties of MnBO3 through the quasi-harmonic Debye model. Finally, its thermal stability at room temperature has been proved in this article by means of ab initio molecular dynamics (AIMD) simulations. We hope that MnBO3 can attract more attention for R3−c-type half-metallic materials with linear band crossings and a high Curie temperature in experimental and theoretical areas.

Very recently, experimentally synthesized R3c phase LaCuO3 was studied by Zhang, Jiao, Kou, Liao & Du [J. Mater. Chem. C (2018), 6, 6132-6137], and they found that this material exhibits multiple Dirac cones in its non-spin-polarized electronic structure. Motivated by this study, the focus here is on a new R3c phase material, AgCuF3, which has a combination of multiple Dirac cones and 100% spin polarization properties. Compared to the non-spin-polarized system LaCuO3, the spin-polarized Dirac behavior in AgCuF3 is intrinsic. The effects of on-site Coulomb interaction, uniform strain and spin-orbit coupling were added to examine the stability of its multiple Dirac cones and half-metallic behavior. Moreover, the thermodynamic properties under different temperatures and pressures were investigated, including the normalized volume, thermal volume expansion coefficient, heat capacity at constant volume and Debye temperature. The thermal stability and the phase stability of this material were also studied via ab initio molecular dynamic simulations and the formation energy of the material, respectively.

In recent years, the search for new Dirac half-metallic materials has been one of the hotspots in the field of spintronics because they have very good physical properties, such as massless Dirac fermions and full spin polarization. In this study, using density function theory combined with the quasi-harmonic Debye model, we show that perovskite-type dysprosium manganite is a novel half metal with multiple Dirac cones. A detailed study of the electronic, magnetic, and thermodynamic properties of DyMnO3 was carried out. Furthermore, the effects of uniform strain, the on-site Coulomb interaction U, spin-orbit coupling, and hole and electron doping on the multiple Dirac cones and full spin polarization were investigated. We should point out that such a spin-polarized Dirac material is rare among perovskite-type compounds. Hence, we hope that, through this work, this kind of material will receive more extensive attention in future studies.

Spin-gapless semiconductors are considered as promising candidates for spintronic and magnetoelectronic materials. Enormous efforts have been devoted to search for materials in this regard. Recently, a new diamond-like quaternary semiconductor CuMn2InSe4 has been successfully synthesized by experiment and also demonstrated as spin-gapless semiconductor in theory. In this work, we report a theoretical study on the electronic, magnetic and thermodynamic properties of the CuMn2InSe4 under strain conditions by employing the first-principles calculations and quasi-harmonic Debye model. Under uniform strain, the spin-gapless semiconducting nature can only be maintained from 0% to 5% at the stretching side yet immediately destroyed at the compressing side. Although the magnetic moments of all atoms vary continuously with uniform strain, the total magnetic moment shows a good stability against uniform stretching up to 5%. The effect of the tetragonal distortion has also been studied in terms of strains in lattice a and c separately. Results show that strain in a has an important impact and induces larger variation on both the electronic and magnetic properties than in c. CuMn2InSe4 easily loses its spin-gapless semiconducting feature with the variation of strain in a but it can be maintained considerably better by strain in c. In particular, this spin-gapless behavior preserves through the whole studied range of strain in c from −5% to +5% at 100% a. While, the magnetic moments of all atoms under tetragonal distortion show the same variation tendencies under strain in a or c and the changing rate is a slightly larger with strain in a. Additionally, the thermodynamic properties of CuMn2InSe4 are predicted through the quasi-harmonic Debye model. The variation of bulk modulus, lattice constant, heat capacity, thermal expansion coefficient, Grüneisen constant and Debye temperature with pressure and temperature are successfully obtained. To the best of our knowledge, neither exp

In this work, a series of all-d-metal Heusler alloys, X 2 - x Mn 1 + x V (X = Pd, Ni, Pt, Ag, Au, Ir, Co; x; = 1, 0), were predicted by first principles. The series can be roughly divided into two categories: XMn 2 V (Mn-rich type) and X 2 MnV (Mn-poor type). Using optimized structural analysis, it is shown that the ground state of these all-d-metal Heusler alloys does not fully meet the site-preference rule for classic full-Heusler alloys. All the Mn-rich type alloys tend to form the L2 1 structure, where the two Mn atoms prefer to occupy the A (0, 0, 0) and C (0.5, 0.5, 0.5) Wyckoff sites, whereas for the Mn-poor-type alloys, some are stable with XA structures and some are not. The c/a ratio was also changed while maintaining the volume the same as in the cubic state to investigate the possible tetragonal transformation of these alloys. The Mn-rich Heusler alloys have strong cubic resistance; however, all the Mn-poor alloys prefer to have a tetragonal state instead of a cubic phase through tetragonal transformations. The origin of the tetragonal state and the competition between the cubic and tetragonal phases in Mn-poor alloys are discussed in detail. Results show that broader and shallower density-of-states structures at or in the vicinity of the Fermi level lower the total energy and stabilize the tetragonal phases of X 2 MnV (X = Pd, Ni, Pt, Ag, Au, Ir, Co). Furthermore, the lack of virtual frequency in the phonon spectra confirms the stability of the tetragonal states of these Mn-poor all-d-metal Heusler alloys. This work provides relevant experimental guidance in the search for possible martensitic Heusler alloys in all-d-metal materials with less Mn and new spintronic and magnetic intelligent materials among all-d-metal Heusler alloys.