Material:

CoAs

ID:

MMD-1425

Explore database:

Compounds with the same formula: CoAs (2 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

orthorhombic

Space group number

62

Hermann-Mauguin

Pnma

Hall

-P 2ac 2n

Point group

mmm

Structure data:

Normalized formula

CoAs

The number of formula units per unit cell

4

The total number of atoms per unit cell

8

The number of inequivalent sites per unit cell

2

Structure search

MP

Lattice parameters:

a (Å)

5.3157

b (Å)

3.4690

c (Å)

5.8250

α (deg.)

90.000

β (deg.)

90.000

γ (deg.)

90.000

Volume (Å3)

107.413

Density (g/cm3)

8.277

Crystal structure visualization:

Thermodynamic properties:

DFT calculations (details)

Formation energy (vs. elemental phases)

-262.7 meV/atom

Formation energy above hull

0 meV, (stable)

Phase diagram:

Phase diagram

Related structures:

Compounds with the same formula: CoAs

2 entries found

Compounds with the same elements: Co-As

9 entries found

Magnetic properties:

DFT calculations (details)

Magnetic ordering

Ferromagnetic

Total magnetic moment

0.53 μB/cell

Averaged magnetic moment

0.07 μB/atom

Magnetic polarization, Js = μ0Ms

0.06 T (= 47.7 emu/cm3)
LMTO-GF calculations (details)

Curie temperature, TC

DFT calculations (details)

Magnetic anisotropy constant, Ka-c

-0.08 MJ/m3 (= -0.06 meV/cell)

Magnetic anisotropy constant, Kb-c

-0.14 MJ/m3 (= -0.09 meV/cell)

Magnetic anisotropy constant, Kb-a

-0.06 MJ/m3 (= -0.04 meV/cell)

Magnetic easy axis

b

Magnetic hardness parameter, κ

7.58

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

index species w x y z m (μB) Esoc100 (meV) Esoc001 (meV)
1 Co 4c 0.750000 0.499057 0.302381 0.14 . .
2 Co 4c 0.750000 0.999057 0.197619 0.14 . .
3 Co 4c 0.250000 0.500943 0.697619 0.14 . .
4 Co 4c 0.250000 0.000943 0.802381 0.14 . .
5 As 4c 0.750000 0.799823 0.588473 -0.00 . .
6 As 4c 0.250000 0.700177 0.088473 -0.00 . .
7 As 4c 0.250000 0.200177 0.411527 -0.00 . .
8 As 4c 0.750000 0.299823 0.911527 -0.00 . .
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 4c 2 Co 4c 1.84 .
1 Co 4c 3 Co 4c 3.52 .
1 Co 4c 4 Co 4c 4.30 .
1 Co 4c 5 As 4c 1.97 .
1 Co 4c 6 As 4c 3.02 .
1 Co 4c 7 As 4c 2.92 .
1 Co 4c 8 As 4c 2.38 .
2 Co 4c 3 Co 4c 4.30 .
2 Co 4c 4 Co 4c 3.52 .
2 Co 4c 5 As 4c 2.38 .
2 Co 4c 6 As 4c 2.92 .
2 Co 4c 7 As 4c 3.02 .
2 Co 4c 8 As 4c 1.97 .
3 Co 4c 4 Co 4c 1.84 .
3 Co 4c 5 As 4c 2.92 .
3 Co 4c 6 As 4c 2.38 .
3 Co 4c 7 As 4c 1.97 .
3 Co 4c 8 As 4c 3.02 .
4 Co 4c 5 As 4c 3.02 .
4 Co 4c 6 As 4c 1.97 .
4 Co 4c 7 As 4c 2.38 .
4 Co 4c 8 As 4c 2.92 .
5 As 4c 6 As 4c 3.96 .
5 As 4c 7 As 4c 3.17 .
5 As 4c 8 As 4c 2.56 .
6 As 4c 7 As 4c 2.56 .
6 As 4c 8 As 4c 3.17 .
7 As 4c 8 As 4c 3.96 .
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) = (18, 12, 10) 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-583
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