Gd–O phases

11 phases (tier A 3, tier C 5, liquid 1, gas 2); 7 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 · Gd–O system page · Markdown · field reference

Phases of the Gd–O system (11)
PhaseStructureBasisStability (calculated)Literature valuesTDB models
B_R2O3
phase:gd-o:b-r2o3
B-Sm2O3 · mC30 · C2/m (12)tier C: assessor-stated (Hallstedt 2025 crystallographic table)not stable in 2 calculated diagram(s)02
BCC_A2
phase:gd-o:bcc-a2
W · A2 · cI2 · Im-3m (229)tier A: standard phase namestable in 1 of 2 calculated diagram(s): 1586.12–2499.87 K, x(O) 0–002
A_R2O3_D52
phase:gd-o:d52-a-r2o3
A-La2O3 · D5_2 · hP5 · P-3m1 (164)tier C: assessor-stated (Hallstedt 2025 crystallographic table)not stable in 2 calculated diagram(s)02
C_R2O3_D53
phase:gd-o:d53-c-r2o3
Mn2O3 · D5_3 · cI80 · Ia-3 (206)tier C: assessor-stated (Hallstedt 2025 crystallographic table)stable in 2 of 2 calculated diagram(s): 300–535 K, x(O) 0.6–0.602
FCC_A1
phase:gd-o:fcc-a1
Cu · A1 · cF4 · Fm-3m (225)tier A: standard phase namenot stable in 2 calculated diagram(s)02
GAS
phase:gd-o:gas
gasgasstable in 2 of 2 calculated diagram(s): 2485–2500 K, x(O) 1–102
H_R2O3
phase:gd-o:h-r2o3
H-La2O3 · hP10 · P6_3/mmc (194)tier C: assessor-stated (Hallstedt 2025 crystallographic table)stable in 2 of 2 calculated diagram(s): 2485–2500 K, x(O) 0.6–0.602
HCP_A3
phase:gd-o:hcp-a3
Mg · A3 · hP2 · P6_3/mmc (194)tier A: standard phase namestable in 2 of 2 calculated diagram(s): 300–325 K, x(O) 0–002
ION
phase:gd-o:ion
liquidliquidstable in 2 of 2 calculated diagram(s): 1586.12–2500 K, x(O) 0–0.5684502
O2GAS
phase:gd-o:o2gas
gasgasstable in 2 of 2 calculated diagram(s): 300–535 K, x(O) 1–102
X_R2O3
phase:gd-o:r2o3-x
Nd2O3 · cI26 · Im-3m (229)tier C: assessor-stated (Hallstedt 2025 crystallographic table)not stable in 2 calculated diagram(s)02

B_R2O3 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:b-r2o3
tdb: tdb:GdO-14McM.tdb:B_R2O3, tdb:GdO-23Nak.tdb:B_R2O3

TDB models of B_R2O3 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: B_R2O3, type code %, sha256 b72717c7ab25c852…

58: PHASE B_R2O3:I % 2 2 3 !
59: CONST B_R2O3:I : GD+3 : O-2 : !

GdO-23Nak.tdb: B_R2O3, type code %, sha256 bd0ea93f229ea2a2…

56: PHASE B_R2O3:I % 2 2 3 !
57: CONST B_R2O3:I : GD+3 : O-2 : !

Example references (2 of 2; assessments first):

BCC_A2 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:bcc-a2
tdb: tdb:GdO-14McM.tdb:BCC_A2, tdb:GdO-23Nak.tdb:BCC_A2

TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: BCC_A2, type code %B, sha256 b72717c7ab25c852…

43: PHASE BCC_A2 %B 2 1 3 !
44: CONST BCC_A2 : GD : VA : !

GdO-23Nak.tdb: BCC_A2, type code %B, sha256 bd0ea93f229ea2a2…

41: PHASE BCC_A2 %B 2 1 3 !
42: CONST BCC_A2 : GD : VA : !

Example references (2 of 2; assessments first):

A_R2O3_D52 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:d52-a-r2o3
tdb: tdb:GdO-14McM.tdb:A_R2O3_D52, tdb:GdO-23Nak.tdb:A_R2O3_D52

TDB models of A_R2O3_D52 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: A_R2O3_D52, type code %, sha256 b72717c7ab25c852…

53: PHASE A_R2O3_D52:I % 2 2 3 !
54: CONST A_R2O3_D52:I : GD+3 : O-2 : !

GdO-23Nak.tdb: A_R2O3_D52, type code %, sha256 bd0ea93f229ea2a2…

51: PHASE A_R2O3_D52:I % 2 2 3 !
52: CONST A_R2O3_D52:I : GD+3 : O-2 : !

Example references (2 of 2; assessments first):

C_R2O3_D53 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:d53-c-r2o3
tdb: tdb:GdO-14McM.tdb:C_R2O3_D53, tdb:GdO-23Nak.tdb:C_R2O3_D53

TDB models of C_R2O3_D53 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: C_R2O3_D53, type code %, sha256 b72717c7ab25c852…

63: PHASE C_R2O3_D53:I % 2 2 3 !
64: CONST C_R2O3_D53:I : GD+3 : O-2 : !

GdO-23Nak.tdb: C_R2O3_D53, type code %, sha256 bd0ea93f229ea2a2…

61: PHASE C_R2O3_D53:I % 2 2 3 !
62: CONST C_R2O3_D53:I : GD+3 : O-2 : !

Example references (2 of 2; assessments first):

FCC_A1 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:fcc-a1
tdb: tdb:GdO-14McM.tdb:FCC_A1, tdb:GdO-23Nak.tdb:FCC_A1

TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: FCC_A1, type code %A, sha256 b72717c7ab25c852…

38: PHASE FCC_A1 %A 2 1 1 !
39: CONST FCC_A1 : GD : VA : !

GdO-23Nak.tdb: FCC_A1, type code %A, sha256 bd0ea93f229ea2a2…

36: PHASE FCC_A1 %A 2 1 1 !
37: CONST FCC_A1 : GD : VA : !

Example references (2 of 2; assessments first):

GAS (Gd–O)

Names (3): corpus: corpus:phase:gd-o:gas
tdb: tdb:GdO-14McM.tdb:GAS, tdb:GdO-23Nak.tdb:GAS

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

GdO-14McM.tdb: GAS, type code %, sha256 b72717c7ab25c852…

76: PHASE GAS:G % 1 1 !
77: CONST GAS:G : GD GDO O O2% O3 : !

GdO-23Nak.tdb: GAS, type code %, sha256 bd0ea93f229ea2a2…

74: PHASE GAS:G % 1 1 !
75: CONST GAS:G : GD GDO O O2% O3 : !

Example references (2 of 2; assessments first):

H_R2O3 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:h-r2o3
tdb: tdb:GdO-14McM.tdb:H_R2O3, tdb:GdO-23Nak.tdb:H_R2O3

TDB models of H_R2O3 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: H_R2O3, type code %, sha256 b72717c7ab25c852…

68: PHASE H_R2O3:I % 2 2 3 !
69: CONST H_R2O3:I : GD+3 : O-2 : !

GdO-23Nak.tdb: H_R2O3, type code %, sha256 bd0ea93f229ea2a2…

66: PHASE H_R2O3:I % 2 2 3 !
67: CONST H_R2O3:I : GD+3 : O-2 : !

Example references (2 of 2; assessments first):

HCP_A3 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:hcp-a3
tdb: tdb:GdO-14McM.tdb:HCP_A3, tdb:GdO-23Nak.tdb:HCP_A3

TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: HCP_A3, type code %A, sha256 b72717c7ab25c852…

48: PHASE HCP_A3 %A 2 1 0.5 !
49: CONST HCP_A3 : GD : VA : !

GdO-23Nak.tdb: HCP_A3, type code %A, sha256 bd0ea93f229ea2a2…

46: PHASE HCP_A3 %A 2 1 0.5 !
47: CONST HCP_A3 : GD : VA : !

Example references (2 of 2; assessments first):

ION (Gd–O)

Names (3): corpus: corpus:phase:gd-o:ion
tdb: tdb:GdO-14McM.tdb:ION, tdb:GdO-23Nak.tdb:ION

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

GdO-14McM.tdb: ION, type code %, sha256 b72717c7ab25c852…

33: PHASE ION:Y % 2 1 1 !
34: CONST ION:Y : GD+3 : O-2 VA : !

GdO-23Nak.tdb: ION, type code %, sha256 bd0ea93f229ea2a2…

31: PHASE ION:Y % 2 1 1 !
32: CONST ION:Y : GD+3 : O-2 VA : !

Example references (2 of 2; assessments first):

O2GAS (Gd–O)

Names (3): corpus: corpus:phase:gd-o:o2gas
tdb: tdb:GdO-14McM.tdb:O2GAS, tdb:GdO-23Nak.tdb:O2GAS

TDB models of O2GAS (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: O2GAS, type code %, sha256 b72717c7ab25c852…

79: PHASE O2GAS % 1 1 !
80: CONST O2GAS : O2 : !

GdO-23Nak.tdb: O2GAS, type code %, sha256 bd0ea93f229ea2a2…

77: PHASE O2GAS % 1 1 !
78: CONST O2GAS : O2 : !

Example references (2 of 2; assessments first):

X_R2O3 (Gd–O)

Names (3): corpus: corpus:phase:gd-o:r2o3-x
tdb: tdb:GdO-14McM.tdb:X_R2O3, tdb:GdO-23Nak.tdb:X_R2O3

TDB models of X_R2O3 (2): PHASE and CONSTITUENT statements as written

GdO-14McM.tdb: X_R2O3, type code %, sha256 b72717c7ab25c852…

73: PHASE X_R2O3:I % 2 2 3 !
74: CONST X_R2O3:I : GD+3 : O-2 : !

GdO-23Nak.tdb: X_R2O3, type code %, sha256 bd0ea93f229ea2a2…

71: PHASE X_R2O3:I % 2 2 3 !
72: CONST X_R2O3:I : GD+3 : O-2 : !

Example references (2 of 2; assessments first):