THE ELECTRONIC BAND STRUCTURES FOR AN ANTIFERROMAGNETIC STATE OF Cu2Sb-TYPE INTERMETALLIC COMPOUND Cr2As

1993 ◽  
Vol 07 (01n03) ◽  
pp. 770-773 ◽  
Author(s):  
M. SHIRAI ◽  
T. KAWAMOTO ◽  
K. MOTIZUKI
Keyword(s):  
Intermetallic Compound ◽  
Electronic Band Structure ◽  
Magnetic Moments ◽  
Partial Density ◽  
Energy Splitting ◽  
Antiferromagnetic State ◽  
Good Correspondence ◽  
Electronic Band ◽  
Linearized Augmented Plane Wave ◽  
Electronic Band Structures

Electronic band structure calculations are carried out for the antiferromagnetic state of an intermetallic compound Cr2As, having the Cu2Sb-type crystal structure, by using a self-consistent linearized augmented-plane-wave (LAPW) method. The partial density of states (DOS) for Cr (II) 3d states shows a small energy splitting (about 1 eV) between the spin-up and spin-down bands, while that for Cr (I) 3d states hardly shows. The magnetic moments at Cr (I) and Cr (II) sites are evaluated to be 0.33μB and 1.37µB per atom, respectively. These values agree well with the observed values. The calculated DOS shows good correspondence with photoemission and inverse photoemission spectra measured recently.

Ab Initio STUDY OF THE MAGNETIC PROPERTIES AND CONDUCTIVE PROPERTIES OF BEST2[Fe(CN)5NO]

2003 ◽  
Vol 02 (03) ◽  
pp. 345-349 ◽  
Author(s):  
W. D. ZOU ◽  
Z. L. LIU ◽  
K. L. YAO
Keyword(s):  
Ab Initio ◽  
Electronic Band Structure ◽  
Magnetic Moments ◽  
Exchange Interactions ◽  
Partial Density ◽  
Full Potential ◽  
Electronic Band ◽  
Nitric Oxide Radical ◽  
A Charge ◽  
Conductive Properties

With the help of the ab initio method of the full potential linearized augmented-plan-wave, electronic band structure and its magnetic property for a charge transfer compound of bis (ethylenediselena)-tetrathiafulvalene (BEST) with [Fe(CN)5NO] anions are studied, where the exchange-correlation effects of electrons are accounted. The partial density of states and atomic spin magnetic moments are calculated and discussed. It is found that the π-electron of the iron atom in the t2g orbital mainly provides the magnetism. Because of the hybridization between oxygen and nitrogen, unpaired electrons localized at the nitric oxide radical contribute the magnetism to the compound. In particular, the calculations of spin magnetic moments reveal that the spin population (spin up and down) of C/Se/S altered in the organic donors, which may lead to antiferromagnetic exchange interactions. We also found that the π-electrons of the 2p-orbital of oxygen, the 2p-orbital of nitrogen, the t2g-orbital of iron, the 2p-orbital of selenium and the 2p-orbital of sulfur contribute to conductivity. These result reveal that the magnetism and conductivity are coexist in the titled compound. Our results are in good agreement with the experiment.

Electronic Band Structures of Intermetallic Compound Cu2Sb

1992 ◽  
Vol 61 (7) ◽  
pp. 2202-2205 ◽  
Author(s):  
Tadaei Ito ◽  
Masafumi Shirai ◽  
Kazuko Motizuki
Keyword(s):  
Intermetallic Compound ◽  
Band Structures ◽  
Electronic Band ◽  
Electronic Band Structures

Research on Topological Insulating Materials Induced by Uniaxial Strains with Properties of Insulating Materials

2013 ◽  
Vol 675 ◽  
pp. 180-183
Author(s):  
Hong Pei Han ◽  
Xin Ping Dong
Keyword(s):  
Electronic Band Structure ◽  
Full Potential ◽  
Electronic Band ◽  
Insulating Materials ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Low Energy Consumption ◽  
Temperature Application ◽  
Insulating Phase ◽  
Linearized Augmented Plane Wave

A series of calculations are carried out to investigate systematically the electronic band structure of bulk HgTe under uniaxial strains with the relaxed-volume by means of the full potential linearized augmented plane-wave method. Our results show that there is a topological insulating phase induced by proper uniaxial strains, which is consistent with previous theoretical and experimental results. Interestingly, the strain-induced band gap is large up to 0.21 and 0.17 eV in expansion and compression along c-direction, respectively. It is indicated that the bulk HgTe under proper uniaxial strains would be possibly made the room temperature application for material engineering with low energy consumption.

Calculated electronic band structure and magnetic moments of ferrites

1992 ◽  
Vol 103 (1-2) ◽  
pp. 212-220 ◽  
Author(s):  
M. Pénicaud ◽  
B. Siberchicot ◽  
C.B. Sommers ◽  
J. Kübler
Keyword(s):  
Band Structure ◽  
Electronic Band Structure ◽  
Magnetic Moments ◽  
Electronic Band

ELECTRONIC BAND STRUCTURES OF ANTIFERROMAGNETIC ORDERED ALLOY FePt3

1993 ◽  
Vol 07 (01n03) ◽  
pp. 765-769 ◽  
Author(s):  
T. SUDA ◽  
M. SHIRAI ◽  
K. MOTIZUKI
Keyword(s):  
Energy Splitting ◽  
Band Structures ◽  
Electronic Band ◽  
Augmented Plane Wave ◽  
Conduction Bands ◽  
Densities Of States ◽  
Self Consistent ◽  
The Difference ◽  
Electronic Band Structures ◽  
Type Crystal

The electronic band structures of an ordered alloy FePt3, having the Cu3Au-type crystal structure, are calculated by using a self-consistent augmented plane wave (APW) method for both non-magnetic (NM) and antiferromagnetic (AF) states. For the NM state, the conduction bands near the Fermi level are hybridized bands which are mainly composed of Fe 3d and Pt 5d orbitals. The Fermi surface shows clearly the nesting feature for the wavevector Q=(π/a, π/a, 0), which would be responsible for the stabilization of the observed AF structure. For the AF state, a large energy splitting of about 4 eV between the spin-up and spin-down bands is found for only Fe 3d states. The magnetic moment at Fe sites is obtained as 3.3µB/Fe, which agrees well with the observed value of 3.3µB/Fe. By comparing the joint densities of states, the difference in optical spectra between the NM and the AF states is clarified.

scholarly journals Finding the Order in Complexity: The Electronic Structure of 14-1-11 Zintl Compounds

2021 ◽  
Author(s):  
Yukun Liu ◽  
Michael Toriyama ◽  
Zizhen Cai ◽  
Mengjia Zhao ◽  
Fei Liu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Molecular Orbital ◽  
Electronic Band Structure ◽  
Orbital Theory ◽  
Electronic Band ◽  
High Performing ◽  
Band Engineering ◽  
Complex Crystal Structure ◽  
P Type ◽  
Electronic Band Structures

Yb14MnSb11 and Yb14MgSb11 have rapidly risen to prominence as high-performing p-type thermoelectric materials for potential deep space power generation. However, the fairly complex crystal structure of 14-1-11 Zintl compounds renders the interpretation of the electronic band structure obscure, making it difficult to chemically guide band engineering and optimization efforts. In this work, we delineate the valence balanced Zintl chemistry of A14MX11 compounds (A = Yb, Ca; M = Mg, Mn, Al, Zn, Cd; X = Sb, Bi) using molecular orbital theory analysis. By analyzing the electronic band structures of Yb14MgSb11 and Yb14AlSb11 , we show that the conduction band minimum is composed of either an antibonding molecular orbital originating from the (Sb3)7− trimer, or a mix of atomic orbitals of A, M, and X. The singly degenerate valence band is comprised of non-bonding Sb p-z orbitals primarily from the Sb atoms in the (MSb4)m- tetrahedra and the of isolated Sb atoms distributed throughout the unit cell. Such a chemical understanding of the electronic structure enables strategies to engineer electronic properties (e.g., the band gap) of A14MX11 compounds.

scholarly journals Momentum-resolved electronic band structure and offsets in an epitaxial NbN/GaN superconductor/semiconductor heterojunction

2021 ◽  
Author(s):  
Tianlun Yu ◽  
John Wright ◽  
Guru Khalsa ◽  
Betül Pamuk ◽  
Celesta Chang ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Photoelectron Spectroscopy ◽  
Electronic Band Structure ◽  
Optical Measurements ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Band Bending ◽  
Interfacial States ◽  
Experimental Findings ◽  
Electronic Band Structures

Abstract The electronic structure of heterointerfaces play a pivotal role in their device functionality. Recently, highly crystalline ultrathin films of superconducting NbN have been integrated by molecular beam epitaxy with the semiconducting GaN. We use soft X-ray angle-resolved photoelectron spectroscopy to directly measure the momentum-resolved electronic band structures for both NbN and GaN constituents of this Schottky heterointerface, and determine their momentum-dependent interfacial band offset as well as the band-bending profile into GaN. We find, in particular, that the Fermi states in NbN are aligned against the band gap in GaN, which excludes any significant electronic cross-talk of the superconducting states in NbN through the interface to GaN. We support the experimental findings with first-principles calculations for bulk NbN and GaN. The Schottky barrier height obtained from photoemission is corroborated by electronic transport and optical measurements. The momentum-resolved understanding of electronic properties elucidated by the combined materials advances and experimental methods in our work opens up new possibilities in systems where interfacial states play a defining role.

Structural, electronic, optical and thermal properties of CuXTe2 (X=Al, Ga, In) compounds: An ab-initio study

2019 ◽  
Vol 33 (07) ◽  
pp. 1950045
Author(s):  
R. Mahdjoubi ◽  
Y. Megdoud ◽  
L. Tairi ◽  
H. Meradji ◽  
Z. Chouahda ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Thermodynamic Conditions ◽  
Structure Density ◽  
First Time ◽  
Linearized Augmented Plane Wave

First-principles calculations of the structural, electronic, optical and thermal properties of chalcopyrite CuXTe2 (X[Formula: see text]=[Formula: see text]Al, Ga, In) have been performed within density functional theory using the full-potential linearized augmented plane wave (FP-LAPW) method, by employing for the exchange and correlation potential the approximations WC-GGA and mBJ-GGA. The effect of X cations replacement on the structural, electronic band structure, density of states and optical properties were highlighted and explained. Our results are in good agreement with the previous theoretical and experimental data. As far as we know, for the first time we find the effects of temperature and pressure on thermal parameters of CuAlTe2 and CuGaTe2 compounds. Thermal properties are very useful for optimizing crystal growth, and predict photovoltaic applications on extreme thermodynamic conditions.

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