Rhombohedral Lanthanum Manganite: a New Class of Dirac Half

Subscriber access provided by University of Sunderland

Functional Inorganic Materials and Devices

Rhombohedral Lanthanum Manganite: a New Class of Dirac Half-Metal with Promising Potential in Spintronics Fengxian Ma, Yalong Jiao, Zhen-Yi Jiang, and Aijun Du ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b09349 • Publication Date (Web): 02 Oct 2018 Downloaded from http://pubs.acs.org on October 5, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Rhombohedral Lanthanum Manganite: a New Class of Dirac Half-Metal with Promising Potential in Spintronics Fengxian Ma 1,2,#, Yalong Jiao2, #, * , Zhenyi Jiang1, and Aijun Du2,* 1

Shaanxi Key Laboratory for Theoretical Physics Frontiers, Institute of Modern Physics, Northwest University, Xi'an 710069, PR China 2

School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Gardens Point Campus, Queensland 4001, Brisbane, Australia

Abstract Dirac half-metals have drawn great scientific interests in spintronics due to their outstanding physical properties such as the large spin polarization and massless Dirac fermions. By using first-principles calculations, we investigate the perovskitetype Lanthanum manganite (LaMnO3) as a novel Dirac half-metal. Specifically, LaMnO3 displays multiple linear band crossings in the spin-up direction, while it has a large bandgap (~ 5 eV) in the spin-down orientation. The intriguing linear band dispersions guarantee the ultra-fast electron transport and the significant band differences between spin up and down direction promise the realization of 100% spin-polarized current and the extremely low energy consumption. Such spinpolarized Dirac material is rare among perovskite-type compounds. By adopting the mean-field theory, the estimated Curie temperature Tc is 438.4 K. Importantly, the LaMnO3 crystal has been experimentally realized two decades ago, which facilitates the future experimental validation. With the novel spin-polarized electronic properties and the high possibility of experimental fabrication, LaMnO3 is ideal for the spintronic application. KEYWORDS:

LaMnO3, perovskite oxides, Dirac half-metal, spintronics, density

functional theory, band structure

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 14

1. INTRODUCTION Faster speed and lower energy consumption represent two ultimate goals for the development of information technology.1-2 Nevertheless, traditional electronics that use the electron’s charge as a degree of freedom for information processing, can hardly meet these requirements because the charge current will inevitably cause the power dissipation according to Ohm’s law.3 By contrast, spin, as the electron’s another degree of freedom, is able to generate the spin current in the information transport which is reversible and non-dissipative as indicated by the generalized Ohm’s law. Possessing such unique transport property, the spin electronics (spintronics) has been subjected to intense scrutiny and undergone fast development over the past two decades.4-15 However, the crucial challenges for the next generation of spintronics are how to endow the electron transport with ultra-high speed and achieve zero energy dissipation. To address these issues, it is vital to search for new materials with linear band crossings (Dirac cone feature) at the Fermi level, and large spin polarization for attaining dissipationless spin current. Under this context, the Dirac half-metal, as one of the most promising candidates for spintronic devices, is proposed in recent years.16 The Dirac half-metal possesses novel Dirac cones in one spin channel while it is semiconducting or insulating in the other direction.

17-22

It can break the time-

reversal symmetry (TRS) regarding a spin-resolved orbital physics, which is distinctly different from non-spin-polarized Dirac structures like graphene18, 23-24. Since charge current and spin current are in different order under TRS, their intrinsic coupling is non-dissipative. Furthermore, Dirac half-metals are also capable of generating 100% spin-polarization and massless Dirac fermions, which are expected to perform better than other spintronic materials such as half-metals,

25

magnetic semiconductors26,

spin gapless semiconductors27-28 and so forth. Therefore, exploring a new family of Dirac half-metals is crucial in boosting the development of spintronic devices. The well-studied lanthanum manganite (LaMnO3) is a perovskite-type oxide ABO3 (A = La, B = Mn) with a space group of Pnma (no. 62). superlattices

33-34

29-32

The LaMnO3 based

were also theoretically investigated regarding the structural and


Page 3 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


electronic properties. In this work, we focus on another phase of LaMnO3 crystal, i.e. the rhombohedral structure with a space group of R-3c (no. 167). This less-studied phase has been fabricated over twenty years,35 whereas its electronic properties have not been explored yet. Based on first-principles calculations, we found this phase displays spin-polarized multiple Dirac cones in the band dispersion, which is very rare among all reported Dirac materials. The calculated Fermi velocities of the cones are comparable to that of graphene. Importantly, LaMnO3 presents novel rings of Dirac points in the Brillouin zone (BZ). The spin-polarized Dirac feature in LaMnO3 is intrinsic and does not require the aid of experimental techniques such as electric field and pressure. 2. COMPUTATIONAL DETAILS The calculations were performed via spin-polarized density functional theory (DFT) as implemented in the VASP code

36-37

. The exchange and correlation functionals

were described by the Perdew−Burke−Ernzerhof (PBE) parameterizaGon of generalized gradient approximation (GGA)38. Dispersion corrections to the total energy

39

were used to incorporate the long-range van der Waals interaction. The

plane-wave basis was set with an energy cut-off of 500 eV. The lattice constant and atomic positions were both optimized until the force and total energy was less than 5 x 10-3 eV/Å and 10−6 eV, respectively. A 5 x 5 x 3 k-point grid was employed in the Monkhorst−Pack scheme. Notice that DFT combined with GGA-PBE functional has the limitation in accurately producing the electronic properties with strongly correlated d electrons in transition metals. The DFT+U method, 40 which introduces onsite Coulomb and exchange interactions into the Hartree-Fock approximation, is used to better describe the strong correlation effect for d electrons and examine the electronic bands of LaMnO3. The band structure of LaMnO3 was also computed through the Heyd-Scuseria-Ernzerhof (HSE06) functional 41. 3. RESULTS AND DISCUSSION The crystal structure of LaMnO3 is shown in Figure 1a. The structure accommodates Mn-centered octahedral with the Mn-O bond length of 1.993 Å. The optimized lattice constants of LaMnO3 are a = b = 5.58 Å and c= 13.34 Å, respectively. These



values agree well with the experimental lattice parameters (a = b = 5.61 Å and c = 13.619 Å). 30 atoms are accommodated in the unit cell with six lanthanum, six manganese, and eighteen oxygen atoms, respectively. Figure 1b depicts three dimensional (3D) magnetic charge density of LaMnO3. It is obvious that magnetic moments are distributed around manganese atoms and the magnetic moment value is calculated to be 24 µB per unit cell.

Figure 1. (a) The optimized structure of the LaMnO3 crystal (hexagonal setting). (b) Three-dimensional magnetic charge density (blue) of LaMnO3. The green, purple and red balls represent lanthanum, manganese, and oxygen atoms, respectively. The magnetic ground state of LaMnO3 was evaluated by constructing ferromagnetic (FM), antiferromagnetic (AFM) and non-magnetic (NM) configurations as shown in Figure 2a-2d. The relative energies for different magnetic structures were calculated by using the PBE + U method with varying Hubbard parameter U (U= 0 ~ 5.0, 10.1) and intra-atomic exchange parameter J (0, 0.88)42 (Table 1). It can be found from Table 1 that the optimized FM state has the lowest energy compared with that in AFM1, AFM2 and NM states and the FM ground state is robust against different U and J values. Notice that the well-known orthorhombic phase LaMnO3 possesses an A type AFM ground state which is different from the FM state in rhombohedral LaMnO3. This can be explained by the reduced octahedral distortion and the change of orbital ordering (to t2g state) in the rhombohedral phase (see the details in Figure S1-S2). In the Stoner model of ferromagnetism.43-44, the number of majority spin electrons N↑in the ferromagnetic system should be more than that of the minority


Page 4 of 14

Page 5 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


spin electrons N↓. As for LaMnO3, the N↑ is 120 while N↓ is only 96, which means

more electrons favor the majority states, resulting in the FM configuration.

Figure 2. Magnetic moment for (a) ferromagnetic (FM), (b-c) antiferromagnetic (AFM1 and AFM2), and (d) non-magnetic (NM) states in LaMnO3. The arrows are spin directions of the manganese atoms. Green, purple and red balls represent lanthanum, manganese, and oxygen atoms, respectively. Table 1: The relative energies (eV) per unit cell among ferromagnetic (FM), antiferromagnetic (AFM1 and AFM2), and non-magnetic states (NM) with varying U and J values. PBE+U

FM

AFM1

AFM2

NM

U=0, J=0

0

1.44 eV

0.34 eV

7.29 eV

U=1.0, J=0

0

1.43 eV

0.52 eV

-

U=2.0, J=0

0

1.47 eV

0.43 eV

-

U=3.0, J=0

0

1.48 eV

0.39 eV

-

U=4.0, J=0

0

1.52 eV

0.39 eV

-

U=5.0, J=0

0

1.58 eV

0.34 eV

-

U=10.1, J=0.88

0

1.84 eV

0.33 eV

-



Figure 3. The band structures of LaMnO3 by (a-b) PBE and (c-d) PBE+U method (U=10.1 eV, J=0.88 eV). The Fermi level is set to zero. M (0, 1/2, 0), Γ (0, 0, 0), K (-1/3, 2/3, 0), H (-1/3, 2/3, 1/2) and A (0, 0, 1/2) are high symmetry points in the first Brillouin zone. Based on the FM ground state, we then illustrate the electronic band structures of LaMnO3 in Figure 3. In Figure 3a, LaMnO3 exhibits multiple linear band dispersions (Dirac cones) in the vicinity of the Fermi level. To be more specific, three cones are distributed along M-Γ line, two cones along Γ-K line, one along H-A line and one at the A point. By considering the symmetry effect in whole BZ, more Dirac points would exist. Furthermore, all cones are distributed in the spin-up states, and a 2.5 eV bandgap in the spin-down channel can be seen (Figure 3b). The Fermi velocity VF was also evaluated by the expression: V

ħ

. Results show that VF for each cone

ranges from 1.35 x 105 m/s to 3.68 x 105 m/s. These values are around one-third of that in graphene (8.5 x 105 m/s). By considering the SOC effect as shown in Figure S3, the Dirac features in LaMnO3 are robust and the SOC only causes small gap openings (up to 31 meV) of some cones. As the SOC effect has a low impact on electronic bands, this material possesses a long spin coherence length that is ideal for spin transport.


Page 6 of 14

Page 7 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


To yield more accurate electronic properties, we calculated the band structure of LaMnO3 within the PBE + U approach using a small Hubbard parameter U = 4 eV, and larger values U= 8.0, 9.0, 10.1 eV with J = 0.88 eV for Mn-3d orbital as illustrated in Figure S4-S5 and Figure 3c-3d, respectively. In the spin-up channel, the PBE + U approach produces the similar band structure compared with the PBE method. But it induces slight gap opening for the Dirac cones, e.g., the cone at the A point displays a gap of 64 meV (Figure 3c).

In the spin-down direction, the incorporation of

parameter U = 10.1 eV and J = 0.88 eV enlarges the bandgap to 4.67 eV and significantly push the conduction bands away from the Fermi level. The HSE06 functional was also used to calculate the band structure for LaMnO3 (Figure S6). It can be found the Dirac feature can be well survived in the spin-up direction, while the HSE06 calculation produces a larger gap in the spin-down channel (approximately 5.30 eV). Note that the band structure along some specific momentum paths cannot fully describe the electronic properties in the whole BZ. We, therefore, present the 3D band dispersion of LaMnO3 to further analyze its Dirac point feature. As shown in Figure S7, LaMnO3 exhibits Dirac rings in the Γ-K-M plane. Such multiple Dirac ring feature is distinctly different from other Dirac materials such as graphene which only display single Dirac cone at the K point. When cation vacancies are introduced in LaMnO3 (Figure S8), we can find the spin-polarized band dispersions can be preserved. But the Dirac cones found in the perfect LaMnO3 will be shifted above the Fermi level and the gap opening will be induced.

Figure 4. Spin-resolved (a) Total and (b) projected density of states of LaMnO3. The Fermi level is set to zero.



Page 8 of 14

Figure 4 depicts the spin-polarized density of states for LaMnO3. In the total density of states (Figure 4a), the valence band maximum is dominated by the electrons from spin-up states, while the conduction bands are both attributed to spin-up and spindown states. By illustrating the projected density of states (Figure 4b), we can find the Dirac cones mainly come from the 3d↑ orbitals of Mn atoms. The spin | ↓ | , here ↑ ↓ |

polarization ratio R can be estimated by | ↑

↑ and ↓ are the DOS

values at the Fermi level for spin-up and down states, respectively. Clearly, the ratio R for LaMnO3 is 100%, indicating its strong ability to generate fully spin-polarized current. To shed light on the origin of orbital contributions for differing Dirac points, the orbital-resolved electronic bands are presented in Figure S9-S11. It can be found the Dirac cones of LaMnO3 are mainly contributed by the and orbitals from Mn atoms. Take the electronic bands along H-A-H line as an example, we now apply the tight-binding (TB) analysis to reproduce the band structure and to explore the physics behind the Dirac cones. The TB Hamiltonian in a localized basis set is as follows,

− ∑ + ℎ. . " + ∑ #

(1)

where # is the on-site energy, is the hopping integral and / is the fermion creation/annihilation operator at site i. By Fourier transform to momentum space, we can obtain the matrix elements of the Hamiltonian in the Bloch basis set,

'() − ∑ '( * +,'( -., (& ''( /0.( − '( , 12 , '(

(2)

here &'( is the wave vector, .( is the position of ith primitive cell, '( is the relative position of jth atom to the primitive cell. As the dominant contributions to valence

and conduction band is from the hybridization of dyz and dxz orbitals of Mn atoms, and the 6 Mn atoms in the unit cell contributes equally to Dirac cones. We simplify the TB model by using one Mn atom and two orbitals (dyz and dxz). The cutoff distance for the hopping term is 3.916 Å, which includes six nearest Mn atoms. Therefore, the Hamiltonian is a simple 2 × 2 matrix which can be written as


Page 9 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


'(" − 5 44 & &'(" 3 64 &'( "

46 &'( " 7 '( " − 5 66 &

(3)

Clearly, the TB band structure shows the feature of Dirac cones and it is in good agreement with the first-principles band structure (Figure 5).

Figure 5. The band structures of LaMnO3 along H-A-H line calculated by (a) TB model and (b) HSE06. The thermal stability and magnetic state of LaMnO3 at room temperature were also examined by performing spin-polarized ab initio molecular dynamics simulations (AIMD). In this calculation, a 2 x 2 x 1 supercell containing 120 atoms was constructed and a Nose-Hoover thermostat at 300 K was employed. After heating up and maintained at the targeted temperature for 20 ps, no structural disruption can be observed (Figure S12). Additionally, the fluctuations of temperature and magnetic moment are displayed in Figure 6a and 6b, respectively. It can be found the ground state remains ferromagnetic and the average value of µB is approximately 23.63, indicating the magnetic moment of LaMnO3 can survive at room temperature. The ferromagnetic ground state at room temperature can be also confirmed by estimating the Curie temperature Tc by the mean-field theory with the formula βKBTc/2=EAFM-EFM, here β is the dimension of the system and kB is Boltzmann constant. EAFM-EFM is the energy difference between AFM and FM state.45 By adopting the PBE result, we find Tc = 438.4 K which is higher than the room temperature, indicating ground state remains ferromagnetic at the room



temperature. We also plot the radial distribution function (RDF) for LaMnO3 at room temperature to evaluate the dynamic change of average bond distance as shown in Figure S13. For the AIMD at 10 ps and 20 ps (Fig. S13a-13b), the first peak of RDF locates at 2.0 Å which corresponds to the average Mn-O bond length at 300 K. This value is very close to the Mn-O bond length at 0 K (1.993 Å), indicating the structure of rhombohedral phase can be preserved at room temperature.

Figure 6. The fluctuations of (a) temperature K and (b) magnetic moment µB as a function of time at 300 K. 4. CONCLUSIONS In summary, we have presented a new member of the Dirac half-metal family in an experimentally synthesized material LaMnO3. With a perovskite-type configuration, LaMnO3 displays spin-polarized multiple Dirac cones and possesses large spin polarization that guarantees the realization of fully spin-polarized current. The reported Dirac cones in LaMnO3 can survive with the use of different methods including PBE, PBE+U, PBE+SOC, and HSE. Our results highlight the intriguing electronic properties in LaMnO3, making it ideal for future spintronic application. ASSOCIATED CONTENTS Supporting Information The Supporting Information is available free of charge on the ACS Publications website.


Page 10 of 14

Page 11 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


The relaxed crystal structure for orthorhombic and rhombohedral LaMnO3; PDOS for orthorhombic and rhombohedral LaMnO3; band structures of rhombohedral LaMnO3 calculated by PBE + SOC, PBE + U (U=4.0|J=0.0, U=8.0|J=0.88, U=9.0|J=0.88, U=10.1|J=0.88 eV) and HSE06 method; 3D band plot of LaMnO3 in the M-K-Γ plane; orbital-resolved band structures; snapshots from AIMD simulation at 300k; radial distribution function (PDF)

AUTHOR INFORMATION Corresponding Authors * Yalong Jiao, Email: [email protected] * Aijun Du, Email: [email protected] Author Contributions #

F. M. and Y. J. contributed equally to this work. All authors have given approval to the final version of the manuscript.

Notes The authors declare no competing financial interest. ACKNOWLEDGEMENTS A.D. acknowledges the financial support by Australian Research Council under Discovery Project (DP170103598) and computer resources provided by National Computational Infrastructure and The Pawsey Supercomputing Centre through the National Computational Merit Allocation Scheme supported by the Australian Government and the Government of Western Australia. Z.J. appreciates the support by the National Natural Science Foundation of China under Grants (No. 51572219, 11447030).

References 1. Li, X.; Yang, J. First-Principles Design of Spintronics Materials. Natl. Sci. Rev. 2016, 3, 365-381.



2. Li, X.; Wu, X. Two-Dimensional Monolayer Designs for Spintronics Applications. Wiley Interdiscip. Rev. Comput. Mol. Sci. 2016, 6, 441-455. 3. Bernevig, B. A.; Zhang, S. Toward Dissipationless Spin Transport in Semiconductors. IBM J. Res. Dev. 2006, 50, 141-148. 4. Wolf, S.; Awschalom, D.; Buhrman, R.; Daughton, J.; Von Molnar, S.; Roukes, M.; Chtchelkanova, A. Y.; Treger, D. Spintronics: A Spin-Based Electronics Vision for the Future. Science 2001, 294, 1488-1495. 5. Žutić, I.; Fabian, J.; Sarma, S. D. Spintronics: Fundamentals and Applications. Rev. Mod. Phy. 2004, 76, 323. 6. Awschalom, D. D.; Flatté, M. E. Challenges for Semiconductor Spintronics. Nat. Phys. 2007, 3, 153-159. 7. Sato, K.; Katayama-Yoshida, H. First Principles Materials Design for Semiconductor Spintronics. Semicond. Sci. Technol. 2002, 17, 367. 8. Crooker, S.; Furis, M.; Lou, X.; Adelmann, C.; Smith, D.; Palmstrøm, C.; Crowell, P. Imaging Spin Transport in Lateral Ferromagnet/Semiconductor Structures. Science 2005, 309, 2191-2195. 9. Jiang, X.; Wang, R.; Shelby, R.; Macfarlane, R.; Bank, S.; Harris, J.; Parkin, S. Highly Spin-Polarized Room-Temperature Tunnel Injector for Semiconductor Spintronics Using Mgo (100). Phys. Rev. Lett. 2005, 94, 056601. 10. Jansen, R. Silicon Spintronics. Nat. Mater. 2012, 11, 400-408. 11. Han, W.; Kawakami, R. K.; Gmitra, M.; Fabian, J. Graphene Spintronics. Nat. Nanotechnol. 2014, 9, 794-807. 12. Wang, X.-L.; Dou, S. X.; Zhang, C. Zero-Gap Materials for Future Spintronics, Electronics and Optics. NPG Asia Mater. 2010, 2, 31. 13. Sun, Y.; Zhuo, Z.; Wu, X.; Yang, J. Room-Temperature Ferromagnetism in TwoDimensional Fe2si Nanosheet with Enhanced Spin-Polarization Ratio. Nano Lett. 2017, 17, 2771-2777. 14. Li, X.; Wu, X.; Yang, J. Room-Temperature Half-Metallicity in La(Mn,Zn)Aso Alloy Via Element Substitutions. J. Am. Chem. Soc. 2014, 136, 5664-5669. 15. Li, X.; Wu, X.; Yang, J. Half-Metallicity in Mnpse3 Exfoliated Nanosheet with Carrier Doping. J. Am. Chem. Soc. 2014, 136, 11065-11069. 16. Ishizuka, H.; Motome, Y. Dirac Half-Metal in a Triangular Ferrimagnet. Phys. Rev. Lett. 2012, 109, 237207. 17. Cai, T.; Li, X.; Wang, F.; Ju, S.; Feng, J.; Gong, C.-D. Single-Spin Dirac Fermion and Chern Insulator Based on Simple Oxides. Nano Lett. 2015, 15, 6434-6439. 18. Li, Y.; West, D.; Huang, H.; Li, J.; Zhang, S. B.; Duan, W. Theory of the Dirac Half Metal and Quantum Anomalous Hall Effect in Mn-Intercalated Epitaxial Graphene. Phys. Rev. B 2015, 92, 201403. 19. Liu, Z.; Liu, J.; Zhao, J. Yn2 Monolayer: Novel P-State Dirac Half Metal for High-Speed Spintronics. Nano Res. 2017, 10, 1972-1979. 20. Wei, L.; Zhang, X.; Zhao, M. Spin-Polarized Dirac Cones and Topological Nontriviality in a Metal–Organic Framework Ni2c24s6h12. Phys. Chem. Chem. Phys. 2016, 18, 8059-8064. 21. He, J.; Li, X.; Lyu, P.; Nachtigall, P. Near-Room-Temperature Chern Insulator and Dirac Spin-Gapless Semiconductor: Nickel Chloride Monolayer. Nanoscale 2017, 9, 22462252. 22. Jiao, Y.; Ma, F.; Zhang, C.; Bell, J.; Sanvito, S.; Du, A. First-Principles Prediction of Spin-Polarized Multiple Dirac Rings in Manganese Fluoride. Phys. Rev. Lett. 2017, 119, 016403. 23. Ma, F.; Jiao, Y.; Gao, G.; Gu, Y.; Bilic, A.; Chen, Z.; Du, A. Graphene-Like TwoDimensional Ionic Boron with Double Dirac Cones at Ambient Condition. Nano Lett. 2016, 16, 3022-3028.


Page 12 of 14

Page 13 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


24. Jiao, Y.; Ma, F.; Bell, J.; Bilic, A.; Du, A. Two‐Dimensional Boron Hydride Sheets: High Stability, Massless Dirac Fermions, and Excellent Mechanical Properties. Angew. Chem. Int. Ed. 2016, 55, 10292-10295. 25. Du, A.; Sanvito, S.; Smith, S. C. First-Principles Prediction of Metal-Free Magnetism and Intrinsic Half-Metallicity in Graphitic Carbon Nitride. Phys. Rev. Lett. 2012, 108, 197207. 26. Li, X.; Wu, X.; Li, Z.; Yang, J.; Hou, J. Bipolar Magnetic Semiconductors: A New Class of Spintronics Materials. Nanoscale 2012, 4, 5680-5685. 27. Wang, X. L. Proposal for a New Class of Materials: Spin Gapless Semiconductors. Phys. Rev. Lett. 2008, 100, 156404. 28. Ouardi, S.; Fecher, G. H.; Felser, C.; Kübler, J. Realization of Spin Gapless Semiconductors: The Heusler Compound Mn2coal. Phys. Rev. Lett. 2013, 110, 100401. 29. Mefford, J. T.; Hardin, W. G.; Dai, S.; Johnston, K. P.; Stevenson, K. J. Anion Charge Storage through Oxygen Intercalation in Lamno3 Perovskite Pseudocapacitor Electrodes. Nat. Mater. 2014, 13, 726-732. 30. Picozzi, S.; Yamauchi, K.; Bihlmayer, G.; Blügel, S. First-Principles Stabilization of an Unconventional Collinear Magnetic Ordering in Distorted Manganites. Phys. Rev. B 2006, 74, 094402. 31. Rivero, P.; Meunier, V.; Shelton, W. Electronic, Structural, and Magnetic Properties of Lamno3 Phase Transition at High Temperature. Phys. Rev. B 2016, 93, 024111. 32. Woodward, P. Octahedral Tilting in Perovskites. Ii. Structure Stabilizing Forces. Acta Crystallogr. B 1997, 53, 44-66. 33. Tahini, H. A.; Cossu, F.; Singh, N.; Smith, S. C.; Schwingenschlögl, U. Electronic Phase Transitions under Hydrostatic Pressure in Lamno3 (111) Bilayers Sandwiched between Laalo3. Phys. Rev. B 2016, 93, 035117. 34. Weng, Y.; Huang, X.; Yao, Y.; Dong, S. Topological Magnetic Phase in Lamno3 (111) Bilayer. Phys. Rev. B 2015, 92, 195114. 35. Norby, P.; Andersen, I. K.; Andersen, E. K.; Andersen, N. The Crystal Structure of Lanthanum Manganate (Iii), Lamno3, at Room Temperature and at 1273 K under N2. J. Solid State Chem. 1995, 119, 191-196. 36. Kresse, G.; Furthmüller, J. Efficient Iterative Schemes for Ab Initio Total-Energy Calculations Using a Plane-Wave Basis Set. Phys. Rev. B 1996, 54, 11169-11186. 37. Kresse, G.; Furthmuller, J. Efficiency of Ab-Initio Total Energy Calculations for Metals and Semiconductors Using a Plane-Wave Basis Set. Comput. Mater. Sci. 1996, 6, 15-50. 38. Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996, 77, 3865-3868. 39. Grimme, S. Semiempirical Gga-Type Density Functional Constructed with a LongRange Dispersion Correction. J. Comput. Chem. 2006, 27, 1787-1799. 40. Anisimov, V. I.; Zaanen, J.; Andersen, O. K. Band Theory and Mott Insulators: Hubbard U Instead of Stoner I. Phys. Rev. B 1991, 44, 943. 41. Heyd, J.; Scuseria, G. E.; Ernzerhof, M. Hybrid Functionals Based on a Screened Coulomb Potential. J. Chem. Phys. 2006, 124, 219906. 42. Satpathy, S.; Popović, Z. S.; Vukajlović, F. R. Electronic Structure of the Perovskite Oxides: La1-Xcaxmno3. Phys. Rev. Lett. 1996, 76, 960-963. 43. Stoner, E. C. Collective Electron Ferromagnetism. Proc. R. Soc. Lond. A Math. Phys. Sci. 1938, 165, 372-414. 44. Collective Electron Ferromagnetism Ii. Energy and Specific Heat. Proc. R. Soc. Lond. A Math. Phys. Sci. 1939, 169, 339-371. 45. Zhou, J.; Wang, Q.; Sun, Q.; Jena, P. Electronic and Magnetic Properties of a Bn Sheet Decorated with Hydrogen and Fluorine. Phys. Rev. B 2010, 81, 085442.



TOC


Page 14 of 14

Rhombohedral Lanthanum Manganite: a New Class of Dirac Half

Recommend Documents