Material:

Co2As

ID:

MMD-1308

Explore database:

Compounds with the same formula: Co2As (3 entries found)
Compounds with the same elements: Co-As (9 entries found)
Navigation:
Space group | Lattice parameters | Thermodynamic properties | Phase diagram | Magnetic properties | Atomic positions and site-specific magnetic data | Pair-wise magnetic data | Methods | References

Space group:

Crystal system

hexagonal

Space group number

189

Hermann-Mauguin

P-62m

Hall

P -6 -2

Point group

-6m2

Structure data:

Normalized formula

Co2As

The number of formula units per unit cell

3

The total number of atoms per unit cell

9

The number of inequivalent sites per unit cell

4

Structure search

MP

Lattice parameters:

a (Å)

5.9842

b (Å)

5.9842

c (Å)

3.5219

α (deg.)

90.000

β (deg.)

90.000

γ (deg.)

120.000

Volume (Å3)

109.224

Density (g/cm3)

8.793

Crystal structure visualization:

Thermodynamic properties:

DFT calculations (details)

Formation energy (vs. elemental phases)

-82.7 meV/atom

Formation energy above hull

92.4 meV/atom

Phase diagram:

Phase diagram

Related structures:

Compounds with the same formula: Co2As

3 entries found

Compounds with the same elements: Co-As

9 entries found

Magnetic properties:

DFT calculations (details)

Magnetic ordering

Ferromagnetic

Total magnetic moment

3.39 μB/cell

Averaged magnetic moment

0.38 μB/atom

Magnetic polarization, Js = μ0Ms

0.36 T (= 286.5 emu/cm3)
LMTO-GF calculations (details)

Curie temperature, TC

DFT calculations (details)

Magnetic anisotropy constant, Ka-c

1.00 MJ/m3 (= 0.68 meV/cell)

Magnetic easy axis

c

Magnetic hardness parameter, κ

3.11

Atomic positions (fractional coordinates) and site-specific magnetic data:

index species w x y z m (μB) Esoc100 (meV) Esoc001 (meV)
1 Co 3f 0.000000 0.743387 0.000000 0.26 . .
2 Co 3f 0.256613 0.256613 0.000000 0.26 . .
3 Co 3f 0.743387 0.000000 0.000000 0.26 . .
4 Co 3g 0.000000 0.401490 0.500000 0.90 . .
5 Co 3g 0.598510 0.598510 0.500000 0.90 . .
6 Co 3g 0.401490 0.000000 0.500000 0.90 . .
7 As 2c 0.333333 0.666667 0.000000 -0.01 . .
8 As 2c 0.666667 0.333333 0.000000 -0.01 . .
9 As 1b 0.000000 0.000000 0.500000 -0.01 . .
w: site multiplicity (the number of equivalent positions) and Wyckoff letter (a label for site symmetry)
m: local magnetic moment
Esoc100 (001): Spin-orbit coupling energy for the magnetization oriented along the crystallographic a (c) axis
(Individual Esoc values are temporarily not available while we perform maintenance.)
Terms and conditions

Site-resolved magnetic moments:

Local magnetic moments

Pair-wise magnetic data:

site i site j distance (Å) Jij (meV)
1 Co 3f 2 Co 3f 2.66 .
1 Co 3f 3 Co 3f 2.66 .
1 Co 3f 4 Co 3g 2.70 .
1 Co 3f 5 Co 3g 2.75 .
1 Co 3f 6 Co 3g 2.75 .
1 Co 3f 7 As 2c 2.26 .
1 Co 3f 8 As 2c 2.26 .
1 Co 3f 9 As 1b 2.34 .
2 Co 3f 3 Co 3f 2.66 .
2 Co 3f 4 Co 3g 2.75 .
2 Co 3f 5 Co 3g 2.70 .
2 Co 3f 6 Co 3g 2.75 .
2 Co 3f 7 As 2c 2.26 .
2 Co 3f 8 As 2c 2.26 .
2 Co 3f 9 As 1b 2.34 .
3 Co 3f 4 Co 3g 2.75 .
3 Co 3f 5 Co 3g 2.75 .
3 Co 3f 6 Co 3g 2.70 .
3 Co 3f 7 As 2c 2.26 .
3 Co 3f 8 As 2c 2.26 .
3 Co 3f 9 As 1b 2.34 .
4 Co 3g 5 Co 3g 3.16 .
4 Co 3g 6 Co 3g 3.16 .
4 Co 3g 7 As 2c 2.54 .
4 Co 3g 8 As 2c 2.54 .
4 Co 3g 9 As 1b 2.40 .
5 Co 3g 6 Co 3g 3.16 .
5 Co 3g 7 As 2c 2.54 .
5 Co 3g 8 As 2c 2.54 .
5 Co 3g 9 As 1b 2.40 .
6 Co 3g 7 As 2c 2.54 .
6 Co 3g 8 As 2c 2.54 .
6 Co 3g 9 As 1b 2.40 .
7 As 2c 8 As 2c 3.45 .
7 As 2c 9 As 1b 3.88 .
8 As 2c 9 As 1b 3.88 .
Jij: magnetic exchange parameter between site i and j (Individual Jij values are temporarily not available while we perform maintenance.)
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Terms and conditions

Pair-resolved magnetic exchange parameters:


Diagram is not available for this entry.

Individual exchange parameters:


Diagram is not available for this entry.

Methods:

DFT calculations

  • exchange-correlation energy functional: GGA-PBE
  • pseudopotential type: PAW
  • cutoff energy: 65.0 Ry
  • k-point grid: (kx, ky, kz) = (12, 12, 18) for magnetic anisotropy calculations
  • package: QE (v6.3)

LMTO-GF calculations

  • k-point grid: (kx, ky, kz) =
  • energy mesh: 41 points on an elliptical contour
  • package: Questaal (v7)

References:

References

Materials Project: mp-1079254
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