O–Zr system

205 accepted literature values from 4 paper(s) (experimental 117, model 85, unspecified 3); 0 calculated phase diagram(s). 16 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · phases (15) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	117
model	85
unspecified	3

Accepted values by property group
Property group	Values
invariant reaction	19
phase transition	54
phase equilibrium	61
formation	26
heat capacity / entropy / enthalpy	26
activity / EMF / Gibbs energy	14
other property	5

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull ZrO-01Lia-LB · CALPHAD hull ZrO-02Arr · CALPHAD hull ZrO-04Che · CALPHAD hull ZrO-04Wan · CALPHAD hull ZrO-06Wan · CALPHAD hull ZrO-98Che

Invariant reactions (literature)

Invariant reactions reported in the literature for the O–Zr system (19)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location	Quote
3067	congruent melting: liquid -> γ-ZrO2	liquid: O 0.6576; γ-ZrO2: O 0.6576	model	[1] Wang 2004	Table 5, p. 9, row 8 report
2983	congruent melting: liquid -> γ-ZrO2	liquid: O 0.666; γ-ZrO2: O 0.666	model	[1] Wang 2004 cites Abriata 1986 doi	Table 5, p. 9, row 7 report
2403.15	congruent melting: L -> HCP	HCP: O 0.25	experimental	[2] Arroyave 2002	Table 1, p. 12, row 7 report
2403	congruent melting: liquid -> hcp	liquid: O 0.25; hcp: O 0.25	model	[1] Wang 2004 cites Abriata 1986 doi	Table 5, p. 9, row 9 report
2402	congruent melting: liquid -> hcp	liquid: O 0.29; hcp: O 0.29	model	[1] Wang 2004	Table 5, p. 9, row 10 report
2400.95	congruent melting: L -> HCP	HCP: O 0.275	model	[2] Arroyave 2002	Table 1, p. 12, row 8 report
2347.15	eutectic: L -> HCP + γ ZrO2-x	L: O 0.4122; HCP: O 0.311; γ ZrO2-x: O 0.6254	model	[2] Arroyave 2002	Table 1, p. 12, row 4 report
2344	eutectic: liquid -> hcp + γ-ZrO2	liquid: O 0.402; hcp: O 0.31; γ-ZrO2: O 0.617	model	[1] Wang 2004	Table 5, p. 9, row 4 report
2338	eutectic: liquid -> hcp + γ-ZrO2	liquid: O 0.4; hcp: O 0.35; γ-ZrO2: O 0.62	model	[1] Wang 2004 cites Abriata 1986 doi	Table 5, p. 9, row 3 report
2335.15	eutectic: L -> HCP + γ ZrO2-x	L: O 0.4; HCP: O 0.35; γ ZrO2-x: O 0.62	experimental	[2] Arroyave 2002	Table 1, p. 12, row 3 report
2250.15	L + (HCP) -> BCC	L: O 0.1003; (HCP): O 0.2217; BCC: O 0.105	model	[2] Arroyave 2002	Table 1, p. 12, row 2 report
2243.15	L + (HCP) -> BCC	L: O 0.1; (HCP): O 0.195; BCC: O 0.105	experimental	[2] Arroyave 2002	Table 1, p. 12, row 1 report
2243.15	peritectic		experimental	[2] Arroyave 2002	p. 2 report	This phase has a maximum oxygen solubility of 10.5 at.% at 1970°C, which is the temperature of the peritectic reaction.
2243	liquid + hcp -> bcc	liquid: O 0.1; hcp: O 0.195; bcc: O 0.105	model	[1] Wang 2004 cites Abriata 1986 doi	Table 5, p. 9, row 1 report
2241	liquid + hcp -> bcc	liquid: O 0.0985; hcp: O 0.19; bcc: O 0.0999	model	[1] Wang 2004	Table 5, p. 9, row 2 report
1803.15	γ ZrO2-x -> HCP + β ZrO2-x	γ ZrO2-x: O 0.6349; HCP: O 0.3041; β ZrO2-x: O 0.665	model	[2] Arroyave 2002	Table 1, p. 12, row 6 report
1799	γ-ZrO2 -> hcp + β-ZrO2	γ-ZrO2: O 0.638; hcp: O 0.309; β-ZrO2: O 0.66667	model	[1] Wang 2004	Table 5, p. 9, row 6 report
1798.15	γ ZrO2-x -> HCP + β ZrO2-x	γ ZrO2-x: O 0.636; HCP: O 0.312; β ZrO2-x: O 0.665	experimental	[2] Arroyave 2002	Table 1, p. 12, row 5 report
1798	γ-ZrO2 -> hcp + β-ZrO2	γ-ZrO2: O 0.636; hcp: O 0.312; β-ZrO2: O 0.665	model	[1] Wang 2004 cites Abriata 1986 doi	Table 5, p. 9, row 5 report

Formation enthalpies

Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from dft_parity.json.

Enthalpies of formation, O–Zr system (26)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location
Zr2O	Zr2O	-286 kJ/mol-atom		model	-192.087 (mp-aaabqwvt)	-186.602 (oqmd-2030404)	[2] Arroyave 2002	Table 3, p. 18, row 11 report
Zr2O	Zr2O	-198 kJ/mol-atom		model	-192.087 (mp-aaabqwvt)	-186.602 (oqmd-2030404)	[2] Arroyave 2002	Table 3, p. 18, row 12 report
Zr3O	Zr3O	-214 kJ/mol-atom		model	-149.095 (mp-aaabfyna)	-142.679 (oqmd-5214)	[2] Arroyave 2002	Table 3, p. 18, row 9 report
Zr3O	Zr3O	-151 kJ/mol-atom		model	-149.095 (mp-aaabfyna)	-142.679 (oqmd-5214)	[2] Arroyave 2002	Table 3, p. 18, row 10 report
Zr6O	Zr6O	-122 kJ/mol-atom		model		-82.626 (oqmd-2132007)	[2] Arroyave 2002	Table 3, p. 18, row 7 report
Zr6O	Zr6O	-93 kJ/mol-atom		model		-82.626 (oqmd-2132007)	[2] Arroyave 2002	Table 3, p. 18, row 8 report
ZrO0.5	Zr2O	-286 kJ/mol-atom		model	-192.087 (mp-aaabqwvt)	-186.602 (oqmd-2030404)	[2] Arroyave 2002	Table 2, p. 17, row 5 report
ZrO0.5	Zr2O	-217 kJ/mol-atom		model	-192.087 (mp-aaabqwvt)	-186.602 (oqmd-2030404)	[2] Arroyave 2002	Table 2, p. 17, row 6 report
ZrO2		-1101 kJ/mol (basis unstated)	298.15	model			[3] CHEN 2004 cites Liang 2001	Table 2, p. 3, row 6 report
ZrO2		-1100.8 kJ/mol (basis unstated)	298.15	experimental			[3] CHEN 2004 cites Huber 1964	Table 2, p. 3, row 2 report
ZrO2		-1100.7 kJ/mol (basis unstated)	298.15	model			[3] CHEN 2004	Table 2, p. 3, row 7 report
ZrO2		-1100.6 kJ/mol (basis unstated)	298.15	experimental			[3] CHEN 2004 cites Kornilov 1967	Table 2, p. 3, row 3 report
ZrO2		-1100.6 kJ/mol (basis unstated)	298.15	model			[3] CHEN 2004 cites Ackermann 1975	Table 2, p. 3, row 4 report
ZrO2		-1097.46 kJ/mol (basis unstated)	298.15	model			[3] CHEN 2004 cites Chase 1985	Table 2, p. 3, row 5 report
ZrO2		-1094.1 kJ/mol (basis unstated)	298.15	experimental			[3] CHEN 2004 cites Humphrey 1954	Table 2, p. 3, row 1 report
ZrO2	ZrO2	-573 kJ/mol-atom		model	-367.957 (mp-aaaaaefy)	-350.528 (oqmd-3278)	[2] Arroyave 2002	Table 2, p. 17, row 1 report
ZrO2	ZrO2	-366 kJ/mol-atom	298.15	experimental	-367.957 (mp-aaaaaefy)	-350.528 (oqmd-3278)	[2] Arroyave 2002	Table 2, p. 17, row 2 report
ZrO3	ZrO3	-644 kJ/mol-atom		model		-239.971 (oqmd-825016)	[2] Arroyave 2002	Table 2, p. 17, row 3 report
ZrO3	ZrO3	-411 kJ/mol-atom		model		-239.971 (oqmd-825016)	[2] Arroyave 2002	Table 2, p. 17, row 4 report
monoclinic ZrO2		-1100.97 kJ/mol (basis unstated)	298.15	model			[1] Wang 2004 cites Liang 2001	Table 3, p. 6, row 8 report
monoclinic ZrO2		-1100.92 kJ/mol (basis unstated)	298.15	experimental			[1] Wang 2004 cites Huber 1964 doi	Table 3, p. 6, row 3 report
monoclinic ZrO2		-1100.69 kJ/mol (basis unstated)	298.15	model			[1] Wang 2004 cites Chen 2004	Table 3, p. 6, row 10 report
monoclinic ZrO2		-1100.57 kJ/mol (basis unstated)	298.15	unspecified			[1] Wang 2004 cites Dinsdale 2003	Table 3, p. 6, row 11 report
monoclinic ZrO2		-1100.57 kJ/mol (basis unstated)	298.15	model			[1] Wang 2004 cites Du 1992 doi	Table 3, p. 6, row 7 report
monoclinic ZrO2		-1100.56 kJ/mol (basis unstated)	298.15	experimental			[1] Wang 2004 cites Kornilov 1967	Table 3, p. 6, row 4 report
monoclinic ZrO2		-1100.31 kJ/mol (basis unstated)	298.15	model			[1] Wang 2004 cites Arroyave 2002 doi	Table 3, p. 6, row 9 report

Other properties

Phase transition (54)

Phase transition, O–Zr system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	973 K	973	polymorphic: α ↔ γ	experimental	[1] Wang 2004 cites Lee 2003 doi	Table 2, p. 5, row 46 report
Phase transition	1043 K	1043	polymorphic: α ↔ γ	experimental	[1] Wang 2004 cites Molodetsky 1998 doi	Table 2, p. 5, row 45 report
Phase transition	1286 K	1286	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Suresh 2003 doi	Table 2, p. 5, row 7 report
Phase transition	1387 K	1387	polymorphic: α ↔ β	model	[1] Wang 2004 cites Chen 2004	Table 2, p. 5, row 14 report
Phase transition	1395 K	1395	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Yashima 1995 doi	Table 2, p. 5, row 5 report
Phase transition	1420 K	1420	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Kirillin 1966	Table 2, p. 5, row 3 report
Phase transition	1423 K	1423	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Ya 1979	Table 2, p. 5, row 4 report
Phase transition	1435 K	1435	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Jerebtsov 2001	Table 2, p. 5, row 6 report
Phase transition	1443 K	1443	polymorphic: α ↔ β	model	[1] Wang 2004 cites Subbarao 1981	Table 2, p. 5, row 9 report
Phase transition	1454 K	1454	polymorphic: α ↔ β	model	[1] Wang 2004 cites Du 1992 doi	Table 2, p. 5, row 11 report
Phase transition	1475 K	1475	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Sh 1965	Table 2, p. 5, row 2 report
Phase transition	1476 K	1476	polymorphic: α ↔ β	model	[1] Wang 2004 cites Liang 2001	Table 2, p. 5, row 12 report
Phase transition	1478 K	1478	polymorphic: m-ZrO2 <-> t-ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Liang 2001	Table 3, p. 5, row 17 report
Phase transition	1478 K	1478	polymorphic: m-ZrO2 <-> t-ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Chase 1985	Table 3, p. 5, row 14 report
Phase transition	1478 K	1478	polymorphic: m-ZrO2 <-> t-ZrO2 alloy: Zr 0.333333	experimental	[3] CHEN 2004 cites Coughlin 1950	Table 3, p. 5, row 1 report
Phase transition	1478 K	1478	polymorphic: m-ZrO2 <-> t-ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Abriata 1986	Table 3, p. 5, row 15 report
Phase transition	1478 K	1478	polymorphic: m-ZrO2 <-> t-ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Ackermann 1975	Table 3, p. 5, row 13 report
Phase transition	1478 K	1478	polymorphic: α ↔ β	model	[1] Wang 2004 cites Ackerman 1975	Table 2, p. 5, row 8 report
Phase transition	1478 K	1478	polymorphic: α ↔ β	experimental	[1] Wang 2004 cites Coughlin 1950 doi	Table 2, p. 5, row 1 report
Phase transition	1478 K	1478	polymorphic: α ↔ β	model	[1] Wang 2004 cites Dinsdale 2003	Table 2, p. 5, row 15 report
Phase transition	1478 K	1478	polymorphic: α ↔ β	model	[1] Wang 2004 cites Arroyave 2002 doi	Table 2, p. 5, row 13 report
Phase transition	1478 K	1478	polymorphic: α ↔ β	model	[1] Wang 2004 cites Abriata 1986 doi	Table 2, p. 5, row 10 report
Phase transition	1478.15 K	1478.15	/3 ZrO2-z + a Zr02_=	experimental	[2] Arroyave 2002 cites Ackerman 1975	p. 3 report	At 1205°C, this phase transforms to a Zr02_= [15].
Phase transition	1798.15 K	1798.15	other: 7 ZrO2-x ~- HCP +/3 Zr02_=	experimental	[2] Arroyave 2002 cites Rauh 1980	p. 3 report	It has also been observed [13] that there exists an invariant transformation 7 ZrO2-x ~- HCP +/3 Zr02_= at 1525°C.
Phase transition	2558 K	2558	polymorphic: β ↔ γ	experimental	[1] Wang 2004 cites Smith 1962	Table 2, p. 5, row 16 report
Phase transition	2566 K	2566	polymorphic: β ↔ γ	experimental	[1] Wang 2004 cites Wolten 1963	Table 2, p. 5, row 17 report
Phase transition	2573 K	2573	polymorphic: β ↔ γ	experimental	[1] Wang 2004 cites Ruh 1970	Table 2, p. 5, row 19 report
Phase transition	2627 K	2627	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Liang 2001	Table 2, p. 5, row 25 report
Phase transition	2641 K	2641	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Arroyave 2002 doi	Table 2, p. 5, row 26 report
Phase transition	2642 K	2642	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Du 1992 doi	Table 2, p. 5, row 24 report
Phase transition	2643 K	2643	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Subbarao 1981	Table 2, p. 5, row 22 report
Phase transition	2645 K	2645	polymorphic: β ↔ γ	experimental	[1] Wang 2004 cites Viechnicki 1965	Table 2, p. 5, row 18 report
Phase transition	2647 K	2647	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Chen 2004	Table 2, p. 5, row 27 report
Phase transition	2650 K	2650	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Abriata 1986 doi	Table 2, p. 5, row 23 report
Phase transition	2650 K	2650	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Ackerman 1975	Table 2, p. 5, row 21 report
Phase transition	2650 K	2650	polymorphic: β ↔ γ	model	[1] Wang 2004 cites Dinsdale 2003	Table 2, p. 5, row 28 report
Phase transition	2650.15 K	2650.15	7 Zr02_= + /3 Zr02-=	experimental	[2] Arroyave 2002 cites Ackerman 1975	p. 3 report	the non-stoichiometric region of the phase being stable at temperatures as low as 1525°C [15], [7], [14] which is much lower than the coherent transformation to the/3 Zr02-= phase(,-, 2377°C [15]).
Phase transition	2950 K	2950	other: γ ↔ L	experimental	[1] Wang 2004 cites Clausing 1932 doi	Table 2, p. 5, row 30 report
Phase transition	2950 K	2950	other: γ ↔ L	model	[1] Wang 2004 cites Arroyave 2002 doi	Table 2, p. 5, row 42 report
Phase transition	2953 K	2953	other: γ ↔ L	experimental	[1] Wang 2004 cites Latta 1970 doi	Table 2, p. 5, row 34 report
Phase transition	2953 K	2953	other: γ ↔ L	model	[1] Wang 2004 cites Subbarao 1981	Table 2, p. 5, row 37 report
Phase transition	2960 K	2960	other: γ ↔ L	experimental	[1] Wang 2004 cites Henning 1925 doi	Table 2, p. 5, row 29 report
Phase transition	2961 K	2961	other: γ ↔ L	model	[1] Wang 2004 cites Liang 2001	Table 2, p. 5, row 41 report
Phase transition	2972 K	2972	other: γ ↔ L	experimental	[1] Wang 2004 cites Noguchi 1966 doi	Table 2, p. 5, row 33 report
Phase transition	2983 K	2983	other: γ ↔ L	model	[1] Wang 2004 cites Du 1992 doi	Table 2, p. 5, row 39 report
Phase transition	2983 K	2983	other: γ ↔ L	experimental	[1] Wang 2004 cites Ackerman 1977	Table 2, p. 5, row 35 report
Phase transition	2983 K	2983	other: γ ↔ L	model	[1] Wang 2004 cites Chen 2004	Table 2, p. 5, row 43 report
Phase transition	2983 K	2983	other: γ ↔ L	experimental	[1] Wang 2004 cites Lambertson 1965	Table 2, p. 5, row 31 report
Phase transition	2983 K	2983	other: γ ↔ L	model	[1] Wang 2004 cites Abriata 1986 doi	Table 2, p. 5, row 38 report
Phase transition	2983.15 K	2983.15	congruent melting	experimental	[2] Arroyave 2002	p. 3 report	The 7 Zr02-= phase exhibits a congruent melting point at 2710°C.
Phase transition	2983.15 K	2983.15	congruent melting	experimental	[2] Arroyave 2002	p. 2 report	It has also been observed that at the stoichiometric composition Zr02, the high temperature cubic phase (7 Zr02_=) melts congruently at 2710°C.
Phase transition	2985 K	2985	other: γ ↔ L	model	[1] Wang 2004 cites Chevalier 1998 doi	Table 2, p. 5, row 40 report
Phase transition	2985 K	2985	other: γ ↔ L	model	[1] Wang 2004 cites Dinsdale 2003	Table 2, p. 5, row 44 report
Phase transition	2995 K	2995	other: γ ↔ L	experimental	[1] Wang 2004 cites Noguchi 1966 doi	Table 2, p. 5, row 32 report

Phase equilibrium (61)

Phase equilibrium, O–Zr system
Property	T (K)	Phases / composition	Class	Source	Location
Phase composition	1530	α + ZrO2 ZrO2: O 0.665, Zr 0.335	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 2 report
Phase composition	1530	β + α + ZrO2 β: O 0.04, Zr 0.96; ZrO2: O 0.665, Zr 0.335	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 1 report
Phase composition	1546	α α: O 0.298, Zr 0.702	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 1 report
Phase composition	1580	α + ZrO2 α: O 0.285, Zr 0.715	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 3 report
Phase composition	1630	α + ZrO2 α: O 0.305, Zr 0.695	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 5 report
Phase composition	1630	β + α β: O 0.059, Zr 0.941; α: O 0.305, Zr 0.695	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 4 report
Phase composition	1730	α + ZrO2 ZrO2: O 0.665, Zr 0.335	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 9 report
Phase composition	1730	α + ZrO2 α: O 0.312, Zr 0.688	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 8 report
Phase composition	1730	β + α α: O 0.15, Zr 0.85	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 7 report
Phase composition	1730	β + α + ZrO2 β: O 0.07, Zr 0.93; α: O 0.312, Zr 0.688; ZrO2: O 0.665, Zr 0.335	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 6 report
Phase composition	1830	α + ZrO2 ZrO2: O 0.635, Zr 0.365	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 13 report
Phase composition	1830	α + ZrO2 α: O 0.304, Zr 0.696	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 12 report
Phase composition	1830	β + α α: O 0.165, Zr 0.835	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 11 report
Phase composition	1830	β + α + ZrO2 β: O 0.082, Zr 0.918; α: O 0.304, Zr 0.696; ZrO2: O 0.635, Zr 0.365	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 10 report
Phase composition	1930	α + ZrO2 α: O 0.317, Zr 0.683	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 16 report
Phase composition	1930	α + ZrO2 ZrO2: O 0.632, Zr 0.368	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 17 report
Phase composition	1930	β + α α: O 0.175, Zr 0.825	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 15 report
Phase composition	1930	β + α + ZrO2 β: O 0.1, Zr 0.9; α: O 0.317, Zr 0.683; ZrO2: O 0.632, Zr 0.368	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 14 report
Phase composition	2030	α + ZrO2 ZrO2: O 0.63, Zr 0.37	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 21 report
Phase composition	2030	α + ZrO2 α: O 0.325, Zr 0.675	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 20 report
Phase composition	2030	β + α α: O 0.182, Zr 0.818	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 19 report
Phase composition	2030	β + α + ZrO2 β: O 0.111, Zr 0.889; α: O 0.325, Zr 0.675; ZrO2: O 0.63, Zr 0.37	experimental	[4] Chevalier 1998 cites Gebhardt 1961 doi	Table 11, p. 12, row 18 report
Phase composition	2088	α + ZrO2 + ZrO2-x ZrO2-x: O 0.6305, Zr 0.3695; ZrO2: O 0.6305, Zr 0.3695	experimental	[4] Chevalier 1998 cites Tanabe 1987 doi	Table 13, p. 13, row 1 report
Phase composition	2089	α α: O 0.329, Zr 0.671	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 2 report
Phase composition	2145	β β: O 0.048, Zr 0.952	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 34 report
Phase composition	2148	α + ZrO2 + ZrO2-x ZrO2-x: O 0.6274, Zr 0.3726; ZrO2: O 0.6274, Zr 0.3726	experimental	[4] Chevalier 1998 cites Tanabe 1987 doi	Table 13, p. 13, row 2 report
Phase composition	2158	α α: O 0.334, Zr 0.666	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 3 report
Phase composition	2191	β β: O 0.073, Zr 0.927	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 33 report
Phase composition	2218	α + ZrO2 + ZrO2-x ZrO2-x: O 0.6256, Zr 0.3744; ZrO2: O 0.6256, Zr 0.3744	experimental	[4] Chevalier 1998 cites Tanabe 1987 doi	Table 13, p. 13, row 3 report
Phase composition	2229	ZrO2 ZrO2: O 0.635, Zr 0.365	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 5 report
Phase composition	2234	L L: O 0.063, Zr 0.937	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 30 report
Phase composition	2241	β β: O 0.094, Zr 0.906	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 32 report
Phase composition	2243	α α: O 0.195, Zr 0.805	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 29 report
Phase composition	2243	α + ZrO2 + ZrO2-x ZrO2-x: O 0.6277, Zr 0.3723; ZrO2: O 0.6277, Zr 0.3723	experimental	[4] Chevalier 1998 cites Tanabe 1987 doi	Table 13, p. 13, row 4 report
Phase composition	2243	β β: O 0.105, Zr 0.895	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 31 report
Phase composition	2253	α α: O 0.337, Zr 0.663	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 4 report
Phase composition	2254	L L: O 0.107, Zr 0.893	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 20 report
Phase composition	2282	ZrO2 ZrO2: O 0.628, Zr 0.372	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 6 report
Phase composition	2293	α + ZrO2 + ZrO2-x ZrO2-x: O 0.6259, Zr 0.3741; ZrO2: O 0.6259, Zr 0.3741	experimental	[4] Chevalier 1998 cites Tanabe 1987 doi	Table 13, p. 13, row 5 report
Phase composition	2297	L L: O 0.12, Zr 0.88	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 21 report
Phase composition	2318	α + ZrO2 + ZrO2-x ZrO2-x: O 0.6221, Zr 0.3779; ZrO2: O 0.6221, Zr 0.3779	experimental	[4] Chevalier 1998 cites Tanabe 1987 doi	Table 13, p. 13, row 6 report
Phase composition	2328	ZrO2 ZrO2: O 0.624, Zr 0.376	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 7 report
Phase composition	2338	L L: O 0.4, Zr 0.6	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 25 report
Phase composition	2338	α α: O 0.35, Zr 0.65	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 26 report
Phase composition	2360	α α: O 0.33, Zr 0.67	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 27 report
Phase composition	2364	ZrO2 ZrO2: O 0.622, Zr 0.378	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 12 report
Phase composition	2381	L L: O 0.33, Zr 0.67	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 24 report
Phase composition	2392	L L: O 0.42, Zr 0.58	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 11 report
Phase composition	2393	L L: O 0.231, Zr 0.769	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 22 report
Phase composition	2396	L L: O 0.412, Zr 0.588	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 9 report
Phase composition	2401	L L: O 0.42, Zr 0.58	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 8 report
Phase composition	2401	L L: O 0.403, Zr 0.597	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 10 report
Phase composition	2403	L L: O 0.24, Zr 0.76	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 23 report
Phase composition	2403	α α: O 0.25, Zr 0.75	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 28 report
Phase composition	2417	ZrO2 ZrO2: O 0.616, Zr 0.384	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 13 report
Phase composition	2475	ZrO2 ZrO2: O 0.613, Zr 0.387	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 14 report
Phase composition	2517	ZrO2 ZrO2: O 0.611, Zr 0.389	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 15 report
Phase composition	2525	ZrO2 ZrO2: O 0.611, Zr 0.389	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 16 report
Phase composition	2586	ZrO2 ZrO2: O 0.608, Zr 0.392	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 17 report
Phase composition	2650	ZrO2 ZrO2: O 0.614, Zr 0.386	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 18 report
Phase composition	2677	ZrO2 ZrO2: O 0.616, Zr 0.384	experimental	[4] Chevalier 1998 cites Ackermann 1977	Table 12, p. 12, row 19 report

Heat capacity / entropy / enthalpy (26)

Heat capacity / entropy / enthalpy, O–Zr system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy printed: S(ZrO2)	50.72 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Liang 2001	Table 1, p. 3, row 6 report
Entropy printed: S(ZrO2)	50.33 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	experimental	[3] CHEN 2004 cites Kelley 1944	Table 1, p. 3, row 1 report
Entropy printed: S(ZrO2)	50.359 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Chase 1985	Table 1, p. 3, row 5 report
Entropy printed: S(ZrO2)	49.79 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	experimental	[3] CHEN 2004 cites Tojo 1999	Table 1, p. 3, row 3 report
Entropy printed: S(ZrO2)	50.71 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Ackermann 1975	Table 1, p. 3, row 4 report
Entropy printed: S(ZrO2)	49.8 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004	Table 1, p. 3, row 7 report
Entropy	50.71 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	experimental	[1] Wang 2004 cites Kelly 1961	Table 3, p. 6, row 2 report
Entropy	49.79 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	experimental	[1] Wang 2004 cites Tojo 1999 doi	Table 3, p. 6, row 6 report
Entropy	49.8 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Chen 2004	Table 3, p. 6, row 10 report
Entropy	50.73 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Liang 2001	Table 3, p. 6, row 8 report
Entropy	50.36 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Arroyave 2002 doi	Table 3, p. 6, row 9 report
Entropy	50.35 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Du 1992 doi	Table 3, p. 6, row 7 report
Entropy	50.35 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	unspecified	[1] Wang 2004 cites Dinsdale 2003	Table 3, p. 6, row 11 report
Heat capacity printed: Cp(ZrO2)	56.5 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	experimental	[3] CHEN 2004 cites Nevitt 1990	Table 1, p. 3, row 2 report
Heat capacity printed: Cp(ZrO2)	63.43 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Liang 2001	Table 1, p. 3, row 6 report
Heat capacity printed: Cp(ZrO2)	56.191 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Chase 1985	Table 1, p. 3, row 5 report
Heat capacity printed: Cp(ZrO2)	56.14 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	experimental	[3] CHEN 2004 cites Tojo 1999	Table 1, p. 3, row 3 report
Heat capacity printed: Cp(ZrO2)	56.02 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004 cites Ackermann 1975	Table 1, p. 3, row 4 report
Heat capacity printed: Cp(ZrO2)	57.21 J/mol (basis unstated)/K	298.15	ZrO2 alloy: Zr 0.333333	model	[3] CHEN 2004	Table 1, p. 3, row 7 report
Heat capacity	56.14 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	experimental	[1] Wang 2004 cites Tojo 1999 doi	Table 3, p. 6, row 6 report
Heat capacity	57.21 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Chen 2004	Table 3, p. 6, row 10 report
Heat capacity	63.43 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Liang 2001	Table 3, p. 6, row 8 report
Heat capacity	56.5 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	experimental	[1] Wang 2004 cites Nevitt 1990 doi	Table 3, p. 6, row 5 report
Heat capacity	55.9 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Arroyave 2002 doi	Table 3, p. 6, row 9 report
Heat capacity	56.12 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	model	[1] Wang 2004 cites Du 1992 doi	Table 3, p. 6, row 7 report
Heat capacity	56.04 J/mol (basis unstated)/K	298.15	monoclinic ZrO2 alloy: Zr 0.333333	unspecified	[1] Wang 2004 cites Dinsdale 2003	Table 3, p. 6, row 11 report

Activity / EMF / Gibbs energy (14)

Activity / EMF / Gibbs energy, O–Zr system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Activity printed: a(Zr)	0.29 unspecified	2100.15		model	[2] Arroyave 2002	p. 16 report	This activity was measured to be 0.68, having pure zirconium at 1827°C as the reference state. Our model predicts that under this conditions, the activity of Zirconium must be 0.29.
Activity printed: a(Zr)	0.68 unspecified	2100.15		experimental	[2] Arroyave 2002	p. 16 report	This activity was measured to be 0.68, having pure zirconium at 1827°C as the reference state.
Activity Zr printed: a(Zr)	0.52 1	1800	Zr (S, saturated with O) + ZrO2-x(S)	experimental	[4] Chevalier 1998 cites Ackermann 1979	Table 15, p. 13, row 1 report
Activity Zr printed: a(Zr)	0.532 1	1800	Zr (S, saturated with O) + ZrO2-x(S)	model	[4] Chevalier 1998	Table 15, p. 13, row 2 report
Activity Zr printed: a(Zr)	0.538 1	1900	Zr (S, saturated with O) + ZrO2-x(S)	model	[4] Chevalier 1998	Table 15, p. 13, row 4 report
Activity Zr printed: a(Zr)	0.57 1	1900	Zr (S, saturated with O) + ZrO2-x(S)	experimental	[4] Chevalier 1998 cites Ackermann 1979	Table 15, p. 13, row 3 report
Activity Zr printed: a(Zr)	0.544 1	2000	Zr (S, saturated with O) + ZrO2-x(S)	model	[4] Chevalier 1998	Table 15, p. 13, row 6 report
Activity Zr printed: a(Zr)	0.62 1	2000	Zr (S, saturated with O) + ZrO2-x(S)	experimental	[4] Chevalier 1998 cites Ackermann 1979	Table 15, p. 13, row 5 report
Activity Zr printed: a(Zr)	0.547 1	2100	Zr (S, saturated with O) + ZrO2-x(S)	model	[4] Chevalier 1998	Table 15, p. 13, row 8 report
Activity Zr printed: a(Zr)	0.67 1	2100	Zr (S, saturated with O) + ZrO2-x(S)	experimental	[4] Chevalier 1998 cites Ackermann 1979	Table 15, p. 13, row 7 report
Activity Zr printed: a(Zr)	0.72 1	2200	Zr (S, saturated with O) + ZrO2-x(S)	experimental	[4] Chevalier 1998 cites Ackermann 1979	Table 15, p. 13, row 9 report
Activity Zr printed: a(Zr)	0.572 1	2200	Zr (S, saturated with O) + ZrO2-x(S)	model	[4] Chevalier 1998	Table 15, p. 13, row 10 report
Activity Zr printed: a(Zr)	0.604 1	2300	Zr (S, saturated with O) + ZrO2-x(S)	model	[4] Chevalier 1998	Table 15, p. 13, row 12 report
Activity Zr printed: a(Zr)	0.78 1	2300	Zr (S, saturated with O) + ZrO2-x(S)	experimental	[4] Chevalier 1998 cites Ackermann 1979	Table 15, p. 13, row 11 report

Other property (5)

Other property, O–Zr system
Property	Value	T (K)	Class	Source	Location	Quote
Other printed: enthalpy of transformation	9700 unspecified ± 1100	973	experimental	[1] Wang 2004 cites Lee 2003 doi	p. 4 report	The enthalpies of formation of cubic yttria-stabilized zirconia with different compositions were measured by high temperature solution calorimetry and oxide melt solution calorimetry [24,25]. The enthalpy of the α ↔ γ transformation was then extrapolated to be 13 500 ± 2200 J mol-1 at 1043 K and 9700 ± 1100 J mol-1 at 973 K, respectively.
Other printed: enthalpy of transformation	13500 unspecified ± 2200	1043	experimental	[1] Wang 2004 cites Molodetsky 1998 doi	p. 4 report	The enthalpies of formation of cubic yttria-stabilized zirconia with different compositions were measured by high temperature solution calorimetry and oxide melt solution calorimetry [24,25]. The enthalpy of the α ↔ γ transformation was then extrapolated to be 13 500 ± 2200 J mol-1 at 1043 K and 9700 ± 1100 J mol-1 at 973 K, respectively.
Other printed: enthalpy of transformation	9200 unspecified ± 1200	1043	model	[1] Wang 2004 cites Molodetsky 1998 doi	p. 4 report	However, Lee et al. [25] also got a modified result 9200 ± 1200 J mol-1 at 1043 K by using the original experimental data of [24].
Other printed: enthalpy of transformation	5175.24 unspecified ± 616.1	1435	experimental	[1] Wang 2004 cites Jerebtsov 2001	p. 4 report	(differential thermal analysis) method, Jerebtsov et al. [19, 23] determined the enthalpy of the α ↔ β transformation in their experimental studies of phase diagrams involving ZrO2 systems, and obtained the value of 5175.24 ± 616.1 J mol-1 at about 1435 K.
Other printed: enthalpy of the α ↔ β transformation	5272 J mol-1	1475	experimental	[1] Wang 2004 cites Sh 1965	p. 4 report	Tsagareishvili and Gvelesiani [16] reported a value of 5272 J mol-1 at 1475 K.

Sources

Reporting papers the values were read from (a value cited from another work names that work in its row).

Chong Wang, Matvei Zinkevich, Fritz Aldinger, On the thermodynamic modeling of the Zr–O system, Calphad 28, 281-292 (2004). doi:10.1016/j.calphad.2004.09.002
Raymundo Arroyave, Larry Kaufman, Thomas W. Eagar, Thermodynamic modeling of the ZrO system, Calphad 26, 95-118 (2002). doi:10.1016/s0364-5916(02)00027-5
M CHEN, B HALLSTEDT, L GAUCKLER, Thermodynamic modeling of the ZrO2–YO1.5 system, Solid State Ionics 170, 255-274 (2004). doi:10.1016/j.ssi.2004.02.017
P.Y. Chevalier, E. Fischer, Thermodynamic modelling of the O–U–Zr system, Journal of Nuclear Materials 257, 213-255 (1998). doi:10.1016/s0022-3115(98)00450-4

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735569
R. Arróyave, J. Saal, D. Shin, ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735891
R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23736065

Also cite the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file. Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes.

@misc{orchid_literature_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735569},
  url       = {https://doi.org/10.5281/zenodo.23735569},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_hulls_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735891},
  url       = {https://doi.org/10.5281/zenodo.23735891}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}