Ba2TlCo2O7
High-Entropy Materials HEAMP-ID: mp-1046346 · Space group: Pmm2 (#25)
Basic Information
Formula
Ba2TlCo2O7
MP-ID
mp-1046346
Elements
4
Sites
12
Density
6.2567
g/cm³
Volume
188.14
ų
Cell a
3.7036
Å
Cell b
3.7097
Å
Cell c
13.6936
Å
α Angle
90.00
°
β Angle
90.00
°
γ Angle
90.00
°
Space Group
Pmm2
Point Group
mm2
Crystal System
Orthorhombic
Bravais Lattice
oP
Stability
No
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 6.45 | 13.6936 | 100.0 | (0,0,1) |
| 19.45 | 4.5645 | 5.2 | (0,0,3) |
| 23.99 | 3.7097 | 1.2 | (0,1,0) |
| 24.03 | 3.7036 | 1.2 | (1,0,0) |
| 26.03 | 3.4234 | 1.8 | (0,0,4) |
| 27.34 | 3.2617 | 45.4 | (0,1,2) |
| 27.38 | 3.2576 | 44.1 | (1,0,2) |
| 31.07 | 2.8789 | 38.8 | (0,1,3) |
| 31.10 | 2.8760 | 39.5 | (1,0,3) |
| 32.70 | 2.7387 | 34.4 | (0,0,5) |
| 34.21 | 2.6210 | 52.8 | (1,1,0) |
| 34.85 | 2.5743 | 21.7 | (1,1,1) |
| 39.48 | 2.2823 | 4.6 | (0,0,6) |
| 43.49 | 2.0811 | 9.7 | (1,1,4) |
| 46.73 | 1.9439 | 1.8 | (0,1,6) |
| 46.75 | 1.9430 | 2.0 | (1,0,6) |
| 48.05 | 1.8936 | 36.2 | (1,1,5) |
| 49.12 | 1.8549 | 13.8 | (0,2,0) |
| 49.20 | 1.8518 | 13.7 | (2,0,0) |
| 49.60 | 1.8381 | 1.8 | (0,2,1) |
| 49.68 | 1.8351 | 1.8 | (2,0,1) |
| 52.91 | 1.7304 | 6.6 | (0,1,7) |
| 52.93 | 1.7298 | 6.4 | (1,0,7) |
| 53.22 | 1.7212 | 6.0 | (1,1,6) |
Energy Properties
Formation Energy/atom
-1.61223
eV/atom
Energy/atom
-6.20490
eV/atom
Energy above Hull
0.2614
eV/atom
Uncorrected Energy
-5.5312
eV/atom
Volume/atom
15.68
ų
c/a Ratio
3.6974
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
7.3851
μB
Mag. Ordering
FM
Mag. Sites
6
Magnetization/Volume
0.039250
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.583
Element Family
Metalloid-Nonmetal
Solute Fraction
0.417
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.1187
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
9.3012
J/mol·K
Ω Parameter
5.8388
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
56.819%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.0322
smaller = more stable mixing
VEC
4.417
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
0.862
kJ/mol; negative = exothermic mixing
Entropy Norm
0.8070
SS Former
0
Phase Tendency
IM
Related Tasks
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-1046346
Reference Citation
The crystal structure and related material properties of Ba2TlCo2O7 were obtained from the Materials Project database (MP-ID: mp-1046346, 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
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Raw CIF Data
# generated using pymatgen
data_Ba2TlCo2O7
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 3.70359900
_cell_length_b 3.70974100
_cell_length_c 13.69363300
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_symmetry_Int_Tables_number 1
_chemical_formula_structural Ba2TlCo2O7
_chemical_formula_sum 'Ba2 Tl1 Co2 O7'
_cell_volume 188.14220618
_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
Ba Ba0 1 0.00000000 0.50000000 0.29464200 1.0
Ba Ba1 1 0.00000000 0.50000000 0.70373000 1.0
Tl Tl2 1 0.50000000 0.00000000 0.49925100 1.0
Co Co3 1 0.50000000 0.00000000 0.12443400 1.0
Co Co4 1 0.50000000 0.00000000 0.87845600 1.0
O O5 1 0.00000000 0.50000000 0.49936000 1.0
O O6 1 0.00000000 0.00000000 0.13244100 1.0
O O7 1 0.50000000 0.50000000 0.13233500 1.0
O O8 1 0.00000000 0.00000000 0.87436400 1.0
O O9 1 0.50000000 0.50000000 0.86296500 1.0
O O10 1 0.50000000 0.00000000 0.34340600 1.0
O O11 1 0.50000000 0.00000000 0.65465100 1.0
