Sr7CaFe6(CoO12)2

High-Entropy Materials HEA

MP-ID: mp-1076372 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

Sr7CaFe6(CoO12)2

MP-ID

mp-1076372

Elements

Sites

Density

5.2270

g/cm³

Volume

473.46

Å³

Cell a

7.7797

Cell b

7.7797

Cell c

7.8227

α Angle

90.00

β Angle

90.00

γ Angle

90.12

Space Group

Amm2

Point Group

mm2

Crystal System

Orthorhombic

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 23)

2θ	d (Å)	I	hkl
11.37	7.7797	1.1	(1,0,0)
32.46	2.7581	100.0	(2,0,2)
32.52	2.7533	24.9	(2,-2,0)
32.59	2.7478	24.8	(2,2,0)
40.05	2.2514	8.9	(2,-2,2)
40.10	2.2484	8.8	(2,2,2)
46.43	1.9557	20.0	(0,0,4)
46.70	1.9449	39.1	(4,0,0)
57.83	1.5944	9.4	(2,-2,4)
57.87	1.5933	9.4	(2,2,4)
57.98	1.5906	18.6	(4,-2,2)
58.07	1.5884	18.5	(4,2,2)
67.98	1.3791	22.4	(4,0,4)
68.11	1.3767	5.6	(4,-4,0)
68.27	1.3739	5.5	(4,4,0)
77.16	1.2362	8.0	(2,0,6)
77.56	1.2308	4.0	(6,-2,0)
77.57	1.2308	7.9	(6,0,2)
77.67	1.2293	3.9	(6,2,0)
82.09	1.1741	1.6	(6,-2,2)
82.20	1.1728	1.6	(6,2,2)
86.44	1.1257	5.5	(4,-4,4)
86.59	1.1242	5.5	(4,4,4)

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Energy Properties

Formation Energy/atom

-2.14932

eV/atom

Energy/atom

-7.09159

eV/atom

Energy above Hull

0.0249

eV/atom

Uncorrected Energy

-6.2591

eV/atom

Volume/atom

11.84

Å³

c/a Ratio

1.0055

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

31.2636

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.066030

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.600

Element Family

Metalloid-Nonmetal

Solute Fraction

0.400

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1381

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.4621

J/mol·K

Ω Parameter

26.6625

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

54.878%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.0383

smaller = more stable mixing

VEC

4.450

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.215

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7071

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaadrplj aaadznim

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1076372

Reference Citation

The crystal structure and related material properties of Sr7CaFe6(CoO12)2 were obtained from the Materials Project database (MP-ID: mp-1076372, 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_Sr7CaFe6(CoO12)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.77973206
_cell_length_b   7.77973206
_cell_length_c   7.82267400
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   90.11551643
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr7CaFe6(CoO12)2
_chemical_formula_sum   'Sr7 Ca1 Fe6 Co2 O24'
_cell_volume   473.46036531
_cell_formula_units_Z   1
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
  Sr  Sr0  1  0.74802800  0.25182300  0.00000000  1.0
  Sr  Sr1  1  0.74812000  0.74812000  0.00000000  1.0
  Sr  Sr2  1  0.25182300  0.74802800  0.00000000  1.0
  Sr  Sr3  1  0.74809000  0.25188200  0.50000000  1.0
  Sr  Sr4  1  0.74816100  0.74816100  0.50000000  1.0
  Sr  Sr5  1  0.25187100  0.25187100  0.50000000  1.0
  Sr  Sr6  1  0.25188200  0.74809000  0.50000000  1.0
  Ca  Ca7  1  0.25192800  0.25192800  0.00000000  1.0
  Fe  Fe8  1  0.00051800  0.00051800  0.75053300  1.0
  Fe  Fe9  1  0.00081000  0.49950200  0.75053000  1.0
  Fe  Fe10  1  0.49950200  0.00081000  0.75053000  1.0
  Fe  Fe11  1  0.00051800  0.00051800  0.24946700  1.0
  Fe  Fe12  1  0.00081000  0.49950200  0.24947000  1.0
  Fe  Fe13  1  0.49950200  0.00081000  0.24947000  1.0
  Co  Co14  1  0.49970700  0.49970700  0.75074500  1.0
  Co  Co15  1  0.49970700  0.49970700  0.24925500  1.0
  O  O16  1  0.00232600  0.00232600  0.00000000  1.0
  O  O17  1  0.00242900  0.49769800  0.00000000  1.0
  O  O18  1  0.49769800  0.00242900  0.00000000  1.0
  O  O19  1  0.49641400  0.49641400  0.00000000  1.0
  O  O20  1  0.00050600  0.00050600  0.50000000  1.0
  O  O21  1  0.00048900  0.49947400  0.50000000  1.0
  O  O22  1  0.49947400  0.00048900  0.50000000  1.0
  O  O23  1  0.49970000  0.49970000  0.50000000  1.0
  O  O24  1  0.74886700  0.00029700  0.75052400  1.0
  O  O25  1  0.74262500  0.49866700  0.75045100  1.0
  O  O26  1  0.25113600  0.00252000  0.75225800  1.0
  O  O27  1  0.25731500  0.49856500  0.75242800  1.0
  O  O28  1  0.74886700  0.00029700  0.24947600  1.0
  O  O29  1  0.74262500  0.49866700  0.24954900  1.0
  O  O30  1  0.25113600  0.00252000  0.24774200  1.0
  O  O31  1  0.25731500  0.49856500  0.24757200  1.0
  O  O32  1  0.00252000  0.25113600  0.75225800  1.0
  O  O33  1  0.00029700  0.74886700  0.75052400  1.0
  O  O34  1  0.49856500  0.25731500  0.75242800  1.0
  O  O35  1  0.49866700  0.74262500  0.75045100  1.0
  O  O36  1  0.00252000  0.25113600  0.24774200  1.0
  O  O37  1  0.00029700  0.74886700  0.24947600  1.0
  O  O38  1  0.49856500  0.25731500  0.24757200  1.0
  O  O39  1  0.49866700  0.74262500  0.24954900  1.0

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