FeCoO4

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-761526 · Space group: P2/c (#13)

Materials Project API

Basic Information

Formula

FeCoO4

MP-ID

mp-761526

Elements

Sites

Density

5.1238

g/cm³

Volume

115.88

Å³

Cell a

5.4690

Cell b

4.3377

Cell c

4.8900

α Angle

87.33

β Angle

90.00

γ Angle

90.00

Space Group

P2/c

Point Group

2/m

Crystal System

Monoclinic

Bravais Lattice

Stability

Packing Fraction

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
16.21	5.4690	2.1	(1,0,0)
26.24	3.3962	100.0	(1,1,0)
31.53	2.8374	91.6	(1,1,1)
32.66	2.7419	79.5	(1,1,-1)
32.75	2.7345	2.8	(2,0,0)
36.80	2.4423	24.1	(0,0,2)
37.70	2.3861	43.7	(2,0,1)
41.59	2.1713	6.5	(0,1,2)
41.69	2.1665	7.9	(0,2,0)
42.85	2.1105	10.0	(2,1,1)
43.37	2.0864	5.3	(0,1,-2)
43.72	2.0703	13.4	(2,1,-1)
44.92	2.0181	16.9	(1,1,2)
46.59	1.9494	16.5	(1,1,-2)
50.08	1.8216	3.5	(2,0,2)
54.00	1.6981	3.0	(2,2,0)
54.62	1.6803	25.0	(3,1,0)
55.36	1.6596	22.1	(0,2,2)
56.74	1.6224	31.5	(2,2,1)
57.69	1.5979	2.1	(3,1,1)
58.16	1.5861	34.1	(2,2,-1)
58.23	1.5845	16.4	(0,2,-2)
58.40	1.5802	3.4	(3,1,-1)
62.34	1.4896	14.0	(1,1,3)

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Energy Properties

Formation Energy/atom

-1.12344

eV/atom

Energy/atom

-7.02266

eV/atom

Energy above Hull

0.1241

eV/atom

Uncorrected Energy

-5.9157

eV/atom

Volume/atom

9.66

Å³

c/a Ratio

0.8941

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

12.0551

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.104030

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.667

Element Family

Metalloid-Nonmetal

Solute Fraction

0.333

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8676

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.2129

J/mol·K

Ω Parameter

41.0942

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

37.733%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.7473

smaller = more stable mixing

VEC

5.500

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-0.111

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7897

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.503

Family

O-rich Multi-Component

Matrix Element

O · 0.667

Related Tasks

Related computation task IDs (5)

aaadoibu aaadvfgv aaadypgo aaaeqhdc aaafbhvg

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-761526

Reference Citation

The crystal structure and related material properties of FeCoO4 were obtained from the Materials Project database (MP-ID: mp-761526, database version v2026.04.13).

Literature Citation

Horton, M.K., Huck, P., Yang, R.X. et al. Accelerated data-driven materials science with the Materials Project. Nat. Mater. 24, 1522–1532 (2025). https://doi.org/10.1038/s41563-025-02272-0

3D Crystal Structure Rendering

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_FeCoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.46903400
_cell_length_b   4.33764600
_cell_length_c   4.88995107
_cell_angle_alpha   87.33011351
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCoO4
_chemical_formula_sum   'Fe2 Co2 O8'
_cell_volume   115.87708391
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Fe  Fe0  1  0.15506900  0.00000000  0.75000000  1.0
  Fe  Fe1  1  0.84493100  0.00000000  0.25000000  1.0
  Co  Co2  1  0.63903900  0.50000000  0.75000000  1.0
  Co  Co3  1  0.36096100  0.50000000  0.25000000  1.0
  O  O4  1  0.87618300  0.24378000  0.91003800  1.0
  O  O5  1  0.39206300  0.27502600  0.92984500  1.0
  O  O6  1  0.39206300  0.72497400  0.57015500  1.0
  O  O7  1  0.87618300  0.75622000  0.58996200  1.0
  O  O8  1  0.12381700  0.24378000  0.41003800  1.0
  O  O9  1  0.60793700  0.27502600  0.42984500  1.0
  O  O10  1  0.60793700  0.72497400  0.07015500  1.0
  O  O11  1  0.12381700  0.75622000  0.08996200  1.0

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