Cr–O phases

11 phases (tier A 6, tier C 1, liquid 2, gas 2); 6 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: interactive registry · full JSON · Cr–O system page · Markdown · field reference

Phases of the Cr–O system (11)
PhaseStructureBasisStability (calculated)Literature valuesTDB models
BCC_A2
phase:cr-o:bcc-a2
W · A2 · cI2 · Im-3m (229)tier A: standard phase namestable in 3 of 3 calculated diagram(s): 300–2179.98 K, x(O) 0–0.0007803
CR2O3_D51
phase:cr-o:cr2o3-d51
alpha-Al2O3 · D5_1 · hR10 · R-3c (167)tier A: standard phase namestable in 3 of 3 calculated diagram(s): 300–2583.7 K, x(O) 0.59163–0.603
CR3O4_H11
phase:cr-o:cr3o4-h11
Al2MgO4 · H1_1 · cF56 · Fd-3m (227)tier A: standard phase namestable in 2 of 2 calculated diagram(s): 1917.97–1973.2 K, x(O) 0.57143–0.5714302
CRO_B1
phase:cr-o:cro-b1
NaCl · B1 · cF8 · Fm-3m (225)tier A: standard phase namenot stable in 1 calculated diagram(s)01
FCC_A1
phase:cr-o:fcc-a1
Cu · A1 · cF4 · Fm-3m (225)tier A: standard phase namenot stable in 3 calculated diagram(s)03
GAS
phase:cr-o:gas
gasgasstable in 3 of 3 calculated diagram(s): 300.1–3913.79 K, x(O) 0–103
SPINEL_H11
phase:cr-o:h11-spinel
Al2MgO4 · H1_1 · cF56 · Fd-3m (227)tier C: assessor-stated (Hallstedt 2025 crystallographic table)not stable in 1 calculated diagram(s)01
HCP_A3
phase:cr-o:hcp-a3
Mg · A3 · hP2 · P6_3/mmc (194)tier A: standard phase namenot stable in 3 calculated diagram(s)03
ION
phase:cr-o:ion
liquidliquidstable in 3 of 3 calculated diagram(s): 1911.97–3913.79 K, x(O) 0–0.603
LIQUID
phase:cr-o:liquid
liquidliquidnot stable in 3 calculated diagram(s)23
O2GAS
phase:cr-o:o2gas
gasgasstable in 3 of 3 calculated diagram(s): 300–1115 K, x(O) 1–103

BCC_A2 (Cr–O)

Names (4): corpus: corpus:phase:cr-o:bcc-a2
tdb: tdb:CrO-06Pov.tdb:BCC_A2, tdb:CrO-10Kje.tdb:BCC_A2, tdb:CrO-90Tay.tdb:BCC_A2

TDB models of BCC_A2 (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: BCC_A2, type code %B, sha256 91b2e0d80ba0b62e…

58: PHASE BCC_A2 %B 2 1 3 !
59: CONST BCC_A2 : CR : O VA% : !

CrO-10Kje.tdb: BCC_A2, type code %B, sha256 ee031ab4eb31aac1…

50: PHASE BCC_A2 %B 2 1 3 !
51: CONST BCC_A2 : CR : O VA : !

CrO-90Tay.tdb: BCC_A2, type code %B, sha256 d075f681078353be…

55: PHASE BCC_A2 %B 2 1 3 !
56: CONST BCC_A2 : CR : O VA : !

Example references (3 of 3; assessments first):

CR2O3_D51 (Cr–O)

Names (4): corpus: corpus:phase:cr-o:cr2o3-d51
tdb: tdb:CrO-06Pov.tdb:CR2O3_D51, tdb:CrO-10Kje.tdb:CR2O3_D51, tdb:CrO-90Tay.tdb:CR2O3_D51

TDB models of CR2O3_D51 (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: CR2O3_D51, type code %, sha256 91b2e0d80ba0b62e…

78: PHASE CR2O3_D51:I % 3 2 1 3 !
79: CONST CR2O3_D51:I : CR+2 CR+3% : CR+3 VA% : O-2 : !

CrO-10Kje.tdb: CR2O3_D51, type code %A, sha256 ee031ab4eb31aac1…

60: PHASE CR2O3_D51:I %A 3 2 1 3 !
61: CONST CR2O3_D51:I : CR+2 CR+3% : CR+3 VA% : O-2 : !

CrO-90Tay.tdb: CR2O3_D51, type code %A, sha256 d075f681078353be…

65: PHASE CR2O3_D51:I %A 3 2 1 3 !
66: CONST CR2O3_D51:I : CR+2 CR+3% : CR+3 VA% : O-2 : !

Example references (3 of 3; assessments first):

CR3O4_H11 (Cr–O)

Names (3): corpus: corpus:phase:cr-o:cr3o4-h11
tdb: tdb:CrO-06Pov.tdb:CR3O4_H11, tdb:CrO-90Tay.tdb:CR3O4_H11

TDB models of CR3O4_H11 (2): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: CR3O4_H11, type code %, sha256 91b2e0d80ba0b62e…

73: PHASE CR3O4_H11:I % 3 1 2 4 !
74: CONST CR3O4_H11:I : CR+2 : CR+3 : O-2 : !

CrO-90Tay.tdb: CR3O4_H11, type code %, sha256 d075f681078353be…

70: PHASE CR3O4_H11:I % 3 2 1 4 !
71: CONST CR3O4_H11:I : CR+3 : CR+2 : O-2 : !

Example references (2 of 2; assessments first):

CRO_B1 (Cr–O)

Names (2): corpus: corpus:phase:cr-o:cro-b1
tdb: tdb:CrO-06Pov.tdb:CRO_B1

TDB models of CRO_B1 (1): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: CRO_B1, type code %, sha256 91b2e0d80ba0b62e…

68: PHASE CRO_B1:I % 2 1 1 !
69: CONST CRO_B1:I : CR+2 : O-2 : !

Example references (1 of 1; assessments first):

FCC_A1 (Cr–O)

Names (4): corpus: corpus:phase:cr-o:fcc-a1
tdb: tdb:CrO-06Pov.tdb:FCC_A1, tdb:CrO-10Kje.tdb:FCC_A1, tdb:CrO-90Tay.tdb:FCC_A1

TDB models of FCC_A1 (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: FCC_A1, type code %A, sha256 91b2e0d80ba0b62e…

53: PHASE FCC_A1 %A 2 1 1 !
54: CONST FCC_A1 : CR : VA : !

CrO-10Kje.tdb: FCC_A1, type code %A, sha256 ee031ab4eb31aac1…

45: PHASE FCC_A1 %A 2 1 1 !
46: CONST FCC_A1 : CR : VA : !

CrO-90Tay.tdb: FCC_A1, type code %A, sha256 d075f681078353be…

50: PHASE FCC_A1 %A 2 1 1 !
51: CONST FCC_A1 : CR : VA : !

Example references (3 of 3; assessments first):

GAS (Cr–O)

Names (4): corpus: corpus:phase:cr-o:gas
tdb: tdb:CrO-06Pov.tdb:GAS, tdb:CrO-10Kje.tdb:GAS, tdb:CrO-90Tay.tdb:GAS

TDB models of GAS (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: GAS, type code %, sha256 91b2e0d80ba0b62e…

84: PHASE GAS:G % 1 1 !
85: CONST GAS:G : CR CR2 CR2O CRO CR2O2 CR2O3 CRO2 CRO3 O O2 O3 : !

CrO-10Kje.tdb: GAS, type code %, sha256 ee031ab4eb31aac1…

73: PHASE GAS:G % 1 1 !
74: CONST GAS:G : CR CR2 CR2O CRO CR2O2 CR2O3 CRO2 CRO3 O O2 O3 : !

CrO-90Tay.tdb: GAS, type code %, sha256 d075f681078353be…

76: PHASE GAS:G % 1 1 !
77: CONST GAS:G : CR CR2 CR2O CRO CR2O2 CR2O3 CRO2 CRO3 O O2 O3 : !

Example references (3 of 3; assessments first):

SPINEL_H11 (Cr–O)

Names (2): corpus: corpus:phase:cr-o:h11-spinel
tdb: tdb:CrO-10Kje.tdb:SPINEL_H11

TDB models of SPINEL_H11 (1): PHASE and CONSTITUENT statements as written

CrO-10Kje.tdb: SPINEL_H11, type code %A, sha256 ee031ab4eb31aac1…

67: PHASE SPINEL_H11:I %A 4 1 2 2 4 !
68: CONST SPINEL_H11:I : CR+2 CR+3 : CR+3 VA : CR+2 VA : O-2 : !

Example references (1 of 1; assessments first):

HCP_A3 (Cr–O)

Names (4): corpus: corpus:phase:cr-o:hcp-a3
tdb: tdb:CrO-06Pov.tdb:HCP_A3, tdb:CrO-10Kje.tdb:HCP_A3, tdb:CrO-90Tay.tdb:HCP_A3

TDB models of HCP_A3 (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: HCP_A3, type code %A, sha256 91b2e0d80ba0b62e…

63: PHASE HCP_A3 %A 2 1 0.5 !
64: CONST HCP_A3 : CR : VA : !

CrO-10Kje.tdb: HCP_A3, type code %A, sha256 ee031ab4eb31aac1…

55: PHASE HCP_A3 %A 2 1 0.5 !
56: CONST HCP_A3 : CR : VA : !

CrO-90Tay.tdb: HCP_A3, type code %A, sha256 d075f681078353be…

60: PHASE HCP_A3 %A 2 1 0.5 !
61: CONST HCP_A3 : CR : VA : !

Example references (3 of 3; assessments first):

ION (Cr–O)

Names (4): corpus: corpus:phase:cr-o:ion
tdb: tdb:CrO-06Pov.tdb:ION, tdb:CrO-10Kje.tdb:ION, tdb:CrO-90Tay.tdb:ION

TDB models of ION (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: ION, type code %, sha256 91b2e0d80ba0b62e…

48: PHASE ION:Y % 2 1 1 !
49: CONST ION:Y : CR+2 CR+3 : O-2 VA : !

CrO-10Kje.tdb: ION, type code %, sha256 ee031ab4eb31aac1…

40: PHASE ION:Y % 2 1 1 !
41: CONST ION:Y : CR+2 : O-2 VA CRO1.5 : !

CrO-90Tay.tdb: ION, type code %, sha256 d075f681078353be…

45: PHASE ION:Y % 2 1 1 !
46: CONST ION:Y : CR+3 : O-2 VA O : !

Example references (3 of 3; assessments first):

LIQUID (Cr–O)

Names (5): corpus: corpus:phase:cr-o:liquid
paper: paper:10.1361/154770306x116289:liquid
tdb: tdb:CrO-06Pov.tdb:LIQUID, tdb:CrO-10Kje.tdb:LIQUID, tdb:CrO-90Tay.tdb:LIQUID

TDB models of LIQUID (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: LIQUID, type code %, sha256 91b2e0d80ba0b62e…

45: PHASE LIQUID:L % 1 1 !
46: CONST LIQUID:L : CR : !

CrO-10Kje.tdb: LIQUID, type code %, sha256 ee031ab4eb31aac1…

37: PHASE LIQUID:L % 1 1 !
38: CONST LIQUID:L : CR : !

CrO-90Tay.tdb: LIQUID, type code %, sha256 d075f681078353be…

42: PHASE LIQUID:L % 1 1 !
43: CONST LIQUID:L : CR : !

Example references (3 of 3; assessments first):

O2GAS (Cr–O)

Names (4): corpus: corpus:phase:cr-o:o2gas
tdb: tdb:CrO-06Pov.tdb:O2GAS, tdb:CrO-10Kje.tdb:O2GAS, tdb:CrO-90Tay.tdb:O2GAS

TDB models of O2GAS (3): PHASE and CONSTITUENT statements as written

CrO-06Pov.tdb: O2GAS, type code %, sha256 91b2e0d80ba0b62e…

81: PHASE O2GAS % 1 1 !
82: CONST O2GAS : O2 :!

CrO-10Kje.tdb: O2GAS, type code %, sha256 ee031ab4eb31aac1…

70: PHASE O2GAS % 1 1 !
71: CONST O2GAS : O2 :!

CrO-90Tay.tdb: O2GAS, type code %, sha256 d075f681078353be…

73: PHASE O2GAS % 1 1 !
74: CONST O2GAS : O2 :!

Example references (3 of 3; assessments first):