Cu–Hf system

156 accepted literature values from 3 paper(s) (experimental 58, model 56, DFT 17, unspecified 25); 3 calculated phase diagram(s). 9 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · interactive phase diagram · phases (9) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	58
model	56
DFT	17
unspecified	25

Accepted values by property group
Property group	Values
invariant reaction	62
phase transition	11
formation	54
crystal structure	29

Calculated phase diagrams

Binary phase diagrams calculated with pycalphad 0.11.2 from the SGTE binary collection (Hallstedt 2025, CC BY 4.0). Evidence class: model.

Assessments with a calculated phase diagram
TDB file	Assessment	SHA-256	Links
CuHf-06Lia.tdb	D. Liang, Y. Liu, J. Alloys Compd., 426, 101-5(2006). doi:10.1016/j.jallcom.2006.02.013	`0c635db89455db2193d2338dc7c2c7254656d48062f08f84dc42892948b58442`	viewer · TDB · JSON
CuHf-08Tur.tdb	M.A. Turchanin, P.G. Agraval, Powder Metall. Met. Ceram., 47, 223-33(2008). doi:10.1007/s11106-008-9008-4	`06d472151340d413caab538d0c986d4360544f591246ec54e843796570015f0d`	viewer · TDB · JSON
CuHf-13Zho.tdb	Y. Zhong, A. Saengdeejing, L. Kecskes. B. Klotz, Z.-K. Liu, Acta Mater., 61, 660-69(2013). doi:10.1016/j.actamat.2012.10.014	`e3133d3e66ab9d10462b3945eeb6ffe7f2f660a143f1f84efa8cd389c04aa7b5`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
CuHf-06Lia.tdb	1813.67	LIQUID (x(Hf) 0.78938) + BCC_A2 (x(Hf) 0.95737) + HCP_A3 (x(Hf) 0.99582)
CuHf-06Lia.tdb	1556.36	CUHF2 (x(Hf) 0.66667) + LIQUID (x(Hf) 0.72905) + HCP_A3 (x(Hf) 0.99379)
CuHf-06Lia.tdb	1556.36	CUHF2 (x(Hf) 0.66667) + LIQUID (x(Hf) 0.729) + HCP_A3 (x(Hf) 0.99379)
CuHf-06Lia.tdb	1326.8	LIQUID (x(Hf) 0.13783) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-06Lia.tdb	1326.8	LIQUID (x(Hf) 0.13807) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-06Lia.tdb	1326.8	LIQUID (x(Hf) 0.13776) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-06Lia.tdb	1263.85	CU51HF14 (x(Hf) 0.21538) + CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.33244)
CuHf-06Lia.tdb	1263.85	CU51HF14 (x(Hf) 0.21538) + CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.33228)
CuHf-06Lia.tdb	1252.99	CU10HF7 (x(Hf) 0.41176) + LIQUID (x(Hf) 0.43637) + CUHF2 (x(Hf) 0.66667)
CuHf-06Lia.tdb	1252.99	CU10HF7 (x(Hf) 0.41176) + LIQUID (x(Hf) 0.43657) + CUHF2 (x(Hf) 0.66667)
CuHf-06Lia.tdb	1235.87	FCC_A1 (x(Hf) 0.00276) + LIQUID (x(Hf) 0.0754) + CU5HF_C15B (x(Hf) 0.16667)
CuHf-06Lia.tdb	1235.87	FCC_A1 (x(Hf) 0.00275) + LIQUID (x(Hf) 0.07535) + CU5HF_C15B (x(Hf) 0.16667)
CuHf-06Lia.tdb	1233.92	CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.35681) + CU10HF7 (x(Hf) 0.41176)
CuHf-06Lia.tdb	1233.92	CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.35693) + CU10HF7 (x(Hf) 0.41176)
CuHf-08Tur.tdb	1815.4	LIQUID (x(Hf) 0.77753) + BCC_A2 (x(Hf) 0.9556) + HCP_A3 (x(Hf) 0.99695)
CuHf-08Tur.tdb	1552.62	CUHF2 (x(Hf) 0.66667) + LIQUID (x(Hf) 0.74041) + HCP_A3 (x(Hf) 0.99773)
CuHf-08Tur.tdb	1313.2	LIQUID (x(Hf) 0.09743) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-08Tur.tdb	1278.48	FCC_A1 (x(Hf) 0.00279) + LIQUID (x(Hf) 0.06787) + CU5HF_C15B (x(Hf) 0.16667)
CuHf-08Tur.tdb	1262.38	CU51HF14 (x(Hf) 0.21538) + CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.38443)
CuHf-08Tur.tdb	1255.81	CU10HF7 (x(Hf) 0.41176) + LIQUID (x(Hf) 0.42092) + CUHF2 (x(Hf) 0.66667)
CuHf-08Tur.tdb	1254.11	CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.39199) + CU10HF7 (x(Hf) 0.41176)
CuHf-08Tur.tdb	321.43	CU51HF14 (x(Hf) 0.21538) + CU8HF3 (x(Hf) 0.27273) + CU10HF7 (x(Hf) 0.41176)
CuHf-13Zho.tdb	1812.79	LIQUID (x(Hf) 0.80631) + BCC_A2 (x(Hf) 0.95774) + HCP_A3 (x(Hf) 0.99908)
CuHf-13Zho.tdb	1571.42	CUHF2 (x(Hf) 0.66667) + LIQUID (x(Hf) 0.72279) + HCP_A3 (x(Hf) 0.99886)
CuHf-13Zho.tdb	1571.42	CUHF2 (x(Hf) 0.66667) + LIQUID (x(Hf) 0.72274) + HCP_A3 (x(Hf) 0.99886)
CuHf-13Zho.tdb	1332.63	LIQUID (x(Hf) 0.13278) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-13Zho.tdb	1332.63	LIQUID (x(Hf) 0.13307) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-13Zho.tdb	1332.63	LIQUID (x(Hf) 0.13262) + CU5HF_C15B (x(Hf) 0.16667) + CU51HF14 (x(Hf) 0.21538)
CuHf-13Zho.tdb	1279.43	LIQUID (x(Hf) 0.40546) + CU10HF7 (x(Hf) 0.41176) + CUHF2 (x(Hf) 0.66667)
CuHf-13Zho.tdb	1279.43	LIQUID (x(Hf) 0.40583) + CU10HF7 (x(Hf) 0.41176) + CUHF2 (x(Hf) 0.66667)
CuHf-13Zho.tdb	1274.49	CU51HF14 (x(Hf) 0.21538) + CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.3478)
CuHf-13Zho.tdb	1274.49	CU51HF14 (x(Hf) 0.21538) + CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.34766)
CuHf-13Zho.tdb	1263.37	CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.35891) + CU10HF7 (x(Hf) 0.41176)
CuHf-13Zho.tdb	1263.37	CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.3588) + CU10HF7 (x(Hf) 0.41176)
CuHf-13Zho.tdb	1263.37	CU8HF3 (x(Hf) 0.27273) + LIQUID (x(Hf) 0.35903) + CU10HF7 (x(Hf) 0.41176)
CuHf-13Zho.tdb	1255.51	FCC_A1 (x(Hf) 0.0042) + LIQUID (x(Hf) 0.07067) + CU5HF_C15B (x(Hf) 0.16667)
CuHf-13Zho.tdb	1255.51	FCC_A1 (x(Hf) 0.0042) + LIQUID (x(Hf) 0.07062) + CU5HF_C15B (x(Hf) 0.16667)

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull CuHf-06Lia · CALPHAD hull CuHf-08Tur

Invariant reactions (literature)

Invariant reactions reported in the literature for the Cu–Hf system (62)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location	Quote
1819	bcc = liquid + hcp	bcc: Hf 0.958; liquid: Hf 0.806; hcp: Hf 0.999	model	[1] Zhong 2013	Table 4, p. 9, row 17 report
1815	(βHf) <=> L + (αHf)	(βHf): Hf 0.997; L: Hf 0.778; (αHf): Hf 0.956	model	[2] Turchanin 2008	Table 1, p. 4, row 11 report
1813.7	bcc -> liquid + hcp	bcc: Hf 0.96; liquid: Hf 0.7894; hcp: Hf 0.996	model	[3] Liang 2006	Table 2, p. 3, row 19 report
1813	bcc -> liquid + hcp	bcc: Hf 0.957; liquid: Hf 0.8; hcp: Hf 0.991	experimental	[3] Liang 2006 cites Pieraggi 1974 doi	Table 2, p. 3, row 20 report
1813	(βHf) <=> L + (αHf)	(βHf): Hf 0.991; (αHf): Hf 0.957	experimental	[2] Turchanin 2008 cites ref. 11	Table 1, p. 4, row 10 report
1813	bcc = liquid + hcp	bcc: Hf 0.957; liquid: Hf 0.8; hcp: Hf 0.991	experimental	[1] Zhong 2013 cites Pieraggi 1974 doi	Table 4, p. 9, row 18 report
1611	congruent melting: L <=> CuHf2	L: Hf 0.6667; CuHf2: Hf 0.6667	model	[2] Turchanin 2008	Table 1, p. 4, row 6 report
1583	congruent melting: L <=> CuHf2	L: Hf 0.6667; CuHf2: Hf 0.6667	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 4, row 5 report
1571	Liquid = CuHf2 + hcp	Liquid: Hf 0.723; CuHf2: Hf 0.667; hcp: Hf 0.999	model	[1] Zhong 2013	Table 4, p. 9, row 15 report
1568.15	eutectic: liquid -> hcp + CuHf2		experimental	[3] Liang 2006 cites Pieraggi 1974 doi	p. 2 report	Pieraggi et al. [17] studied the Hf-rich portion of the Cu-Hf system between 72.7 and 100 at.% Hf using DTA and metallography. It was discovered that the eutectic decomposition of the liquid Cu-Hf alloy into hcp and CuHf2 appeared at 1295 ◦ C.
1568	eutectic: Liquid -> CuHf2 + hcp	L: Hf 0.732; CuHf2: Hf 0.666667	experimental	[1] Zhong 2013 cites Pieraggi 1974 doi	Table 4, p. 9, row 26 report
1568	L <=> CuHf2 + (αHf)	CuHf2: Hf 0.6667	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 4, row 7 report
1568	eutectic: Liquid -> CuHf2 + hcp	L: Hf 0.72; CuHf2: Hf 0.666667	experimental	[1] Zhong 2013 cites Markiv 1974	Table 4, p. 9, row 25 report
1568	eutectic: Liquid -> CuHf2 + hcp	Liquid: Hf 0.732; CuHf2: Hf 0.666667	experimental	[3] Liang 2006 cites Pieraggi 1974 doi	Table 2, p. 3, row 18 report
1568	L <=> CuHf2 + (αHf)	CuHf2: Hf 0.6667; (αHf): Hf 0.997	experimental	[2] Turchanin 2008 cites ref. 11	Table 1, p. 4, row 8 report
1556.4	eutectic: Liquid -> CuHf2 + hcp	Liquid: Hf 0.729; CuHf2: Hf 0.666667	model	[3] Liang 2006	Table 2, p. 3, row 17 report
1552	L <=> CuHf2 + (αHf)	L: Hf 0.74; CuHf2: Hf 0.6667; (αHf): Hf 0.998	model	[2] Turchanin 2008	Table 1, p. 4, row 9 report
1385	congruent melting: L -> Cu51Hf14	L: Hf 0.2154; Cu51Hf14: Hf 0.2154	model	[2] Turchanin 2008	Table 1, p. 3, row 9 report
1383	congruent melting: L -> Cu51Hf14	L: Hf 0.25; Cu51Hf14: Hf 0.25	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 3, row 8 report
1333	Cu5Hf = liquid + Cu51Hf14	Cu5Hf: Hf 0.167; liquid: Hf 0.133; Cu51Hf14: Hf 0.215	model	[1] Zhong 2013	Table 4, p. 9, row 3 report
1328	Cu5Hf = liquid + Cu51Hf14	Cu5Hf: Hf 0.166667; liquid: Hf 0.126; Cu51Hf14: Hf 0.215385	experimental	[1] Zhong 2013 cites Perry 1974 doi	Table 4, p. 9, row 4 report
1328	L + Cu51Hf14 -> Cu5Hf	Cu51Hf14: Cu 0.784615, Hf 0.215385; Cu5Hf: Hf 0.1667	experimental	[2] Turchanin 2008 cites ref. 9	Table 1, p. 3, row 6 report
1328	Cu5Hf -> liquid + Cu51Hf14	Cu5Hf: Hf 0.166667; liquid: Hf 0.126; Cu51Hf14: Hf 0.215385	experimental	[3] Liang 2006 cites Perry 1974 doi	Table 2, p. 3, row 4 report
1326.8	Cu5Hf -> liquid + Cu51Hf14	Cu5Hf: Hf 0.166667; liquid: Hf 0.138; Cu51Hf14: Hf 0.215385	model	[3] Liang 2006	Table 2, p. 3, row 3 report
1313	L + Cu51Hf14 -> Cu5Hf	L: Hf 0.097; Cu51Hf14: Hf 0.2154; Cu5Hf: Hf 0.1667	model	[2] Turchanin 2008	Table 1, p. 3, row 7 report
1298	Cu10Hf7 = Liquid + CuHf2	Cu10Hf7: Hf 0.411765; Liquid: Hf 0.4; CuHf2: Hf 0.666667	experimental	[1] Zhong 2013 cites Woodman 2006 doi	Table 4, p. 9, row 12 report
1288	congruent melting: L <=> Cu10Hf7	L: Hf 0.4; Cu10Hf7: Hf 0.4	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 4, row 1 report
1279	Cu10Hf7 = Liquid + CuHf2	Cu10Hf7: Hf 0.412; Liquid: Hf 0.405; CuHf2: Hf 0.667	model	[1] Zhong 2013	Table 4, p. 9, row 11 report
1278	eutectic: L -> (Cu) + Cu5Hf	L: Hf 0.068; (Cu): Hf 0.003; Cu5Hf: Hf 0.1667	model	[2] Turchanin 2008	Table 1, p. 3, row 5 report
1275	peritectic: liquid + CuHf2 = Cu10 Hf7		experimental	[1] Zhong 2013	p. 4 report	Nevertheless, the invariant temperature for the peritectic reaction liquid + CuHf2 = Cu10 Hf7 was determined to be 1275 K.
1275	Cu10Hf7 -> Liquid + CuHf2	Cu10Hf7: Hf 0.411765; CuHf2: Hf 0.666667	experimental	[1] Zhong 2013	Table 4, p. 9, row 24 report
1274	Cu8Hf3 = Cu51Hf14 + liquid	Cu8Hf3: Hf 0.273; Cu51Hf14: Hf 0.215; liquid: Hf 0.348	model	[1] Zhong 2013	Table 4, p. 9, row 7 report
1263.8	Cu8Hf3 -> Cu51Hf14 + liquid	Cu8Hf3: Hf 0.272727; Cu51Hf14: Hf 0.215385; liquid: Hf 0.332	model	[3] Liang 2006	Table 2, p. 3, row 7 report
1263	L + Cu51Hf14 -> Cu8Hf3	Cu51Hf14: Hf 0.25; Cu8Hf3: Hf 0.2857	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 3, row 10 report
1263	L + Cu51Hf14 -> Cu8Hf3	L: Hf 0.384; Cu51Hf14: Hf 0.2154; Cu8Hf3: Hf 0.2727	model	[2] Turchanin 2008	Table 1, p. 3, row 12 report
1263	Liquid = Cu8Hf3 + Cu10Hf7	Liquid: Hf 0.359; Cu8Hf3: Hf 0.273; Cu10Hf7: Hf 0.412	model	[1] Zhong 2013	Table 4, p. 9, row 9 report
1263	Cu8Hf3 = Cu51Hf14 + liquid	Cu8Hf3: Hf 0.272727; Cu51Hf14: Hf 0.215385; liquid: Hf 0.34	experimental	[1] Zhong 2013 cites Markiv 1974	Table 4, p. 9, row 8 report
1263	L + Cu51Hf14 -> Cu8Hf3	L: Hf 0.33; Cu51Hf14: Hf 0.2154; Cu8Hf3: Hf 0.2727	model	[2] Turchanin 2008 cites ref. 13	Table 1, p. 3, row 11 report
1263	Cu8Hf3 -> Cu51Hf14 + liquid	Cu8Hf3: Hf 0.272727; Cu51Hf14: Hf 0.215385; liquid: Hf 0.34	experimental	[3] Liang 2006 cites Subramanian 1988 doi	Table 2, p. 3, row 8 report
1261	Liquid = Cu51Hf14 + Cu10Hf7	Liquid: Hf 0.355; Cu51Hf14: Hf 0.215; Cu10Hf7: Hf 0.412	model	[1] Zhong 2013	Table 4, p. 9, row 19 report
1261	eutectic: L -> (Cu) + Cu5Hf	L: Hf 0.0775; Cu5Hf: Hf 0.1667	experimental	[2] Turchanin 2008 cites ref. 9	Table 1, p. 3, row 3 report
1261	eutectic: Liquid -> fcc + Cu5Hf	L: Hf 0.078; Cu5Hf: Hf 0.166667	experimental	[1] Zhong 2013 cites Perry 1974 doi	Table 4, p. 9, row 21 report
1256	congruent melting: L <=> Cu10Hf7	L: Hf 0.4118; Cu10Hf7: Hf 0.4118	model	[2] Turchanin 2008	Table 1, p. 4, row 2 report
1256	Liquid = fcc + Cu5Hf	Liquid: Hf 0.071; fcc: Hf 0.004; Cu5Hf: Hf 0.167	model	[1] Zhong 2013	Table 4, p. 9, row 1 report
1255	L <=> Cu10Hf7 + CuHf2	L: Hf 0.421; Cu10Hf7: Hf 0.4118; CuHf2: Hf 0.6667	model	[2] Turchanin 2008	Table 1, p. 4, row 4 report
1254	eutectic: L -> Cu8Hf3 + Cu10Hf7	L: Hf 0.392; Cu8Hf3: Hf 0.2727; Cu10Hf7: Hf 0.4118	model	[2] Turchanin 2008	Table 1, p. 3, row 14 report
1253.15	eutectic		experimental	[3] Liang 2006 cites Perry 1974 doi	p. 2 report	Perry et al. [18] established the Cu-rich end of the Cu-Hf system by DTA, metallography and electron microprobe analysis. A terminal eutectic between fcc solid solution and Cu5 Hf at 7.75 at.% Hf and 980 ◦ C was observed, which is in disagreement with the data of Markiv et al. [15].
1253	L <=> Cu10Hf7 + CuHf2	L: Hf 0.436; Cu10Hf7: Hf 0.4; CuHf2: Hf 0.6667	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 4, row 3 report
1253	eutectic: Liquid -> Cu10Hf7 + CuHf2	Liquid: Hf 0.436; Cu10Hf7: Hf 0.411765; CuHf2: Hf 0.666667	experimental	[3] Liang 2006 cites Subramanian 1988 doi	Table 2, p. 3, row 14 report
1253	eutectic: Liquid -> Cu10Hf7 + CuHf2	Liquid: Hf 0.436; Cu10Hf7: Hf 0.411765; CuHf2: Hf 0.666667	model	[3] Liang 2006	Table 2, p. 3, row 13 report
1250	eutectic: Liquid -> fcc + Cu5Hf	fcc: Hf 0.003; Cu5Hf: Hf 0.166667	experimental	[1] Zhong 2013 cites Watanabe 1967	Table 4, p. 9, row 20 report
1243	eutectic: L -> Cu8Hf3 + Cu10Hf7	L: Hf 0.366; Cu8Hf3: Hf 0.2857; Cu10Hf7: Hf 0.4	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 3, row 13 report
1243	eutectic: Liquid -> fcc + Cu5Hf	fcc: Hf 0.003; Cu5Hf: Hf 0.166667	experimental	[1] Zhong 2013 cites Saarivirta 1963	Table 4, p. 9, row 23 report
1243	Liquid = Cu8Hf3 + Cu10Hf7	Liquid: Hf 0.386; Cu8Hf3: Hf 0.272727; Cu10Hf7: Hf 0.411765	experimental	[1] Zhong 2013 cites Markiv 1974	Table 4, p. 9, row 10 report
1243	eutectic: L -> (Cu) + Cu5Hf	(Cu): Hf 0.0034; Cu5Hf: Cu 0.833333, Hf 0.166667	experimental	[2] Turchanin 2008 cites ref. 8	Table 1, p. 3, row 2 report
1243	eutectic: Liquid -> Cu8Hf3 + Cu10Hf7	Liquid: Hf 0.386; Cu8Hf3: Hf 0.272727; Cu10Hf7: Hf 0.411765	experimental	[3] Liang 2006 cites Subramanian 1988 doi	Table 2, p. 3, row 10 report
1238	eutectic: L -> (Cu) + Cu5Hf	(Cu): Hf 0.0031; Cu5Hf: Cu 0.833333, Hf 0.166667	experimental	[2] Turchanin 2008 cites ref. 7	Table 1, p. 3, row 1 report
1235.9	eutectic: Liquid -> fcc + Cu5Hf	Liquid: Hf 0.075; fcc: Hf 0.003; Cu5Hf: Hf 0.166667	model	[3] Liang 2006	Table 2, p. 3, row 1 report
1233.9	eutectic: Liquid -> Cu8Hf3 + Cu10Hf7	Liquid: Hf 0.357; Cu8Hf3: Hf 0.272727; Cu10Hf7: Hf 0.411765	model	[3] Liang 2006	Table 2, p. 3, row 9 report
1223	eutectic: Liquid -> fcc + Cu5Hf	Liquid: Hf 0.078; fcc: Hf 0; Cu5Hf: Hf 0.166667	experimental	[3] Liang 2006 cites Markiv 1974	Table 2, p. 3, row 2 report
1223	eutectic: Liquid -> fcc + Cu5Hf	L: Hf 0.078; Cu5Hf: Hf 0.166667	experimental	[1] Zhong 2013 cites Markiv 1974	Table 4, p. 9, row 22 report
1223	eutectic: L -> (Cu) + Cu5Hf	L: Hf 0.06; Cu5Hf: Cu 0.833333, Hf 0.166667	experimental	[2] Turchanin 2008 cites ref. 10	Table 1, p. 3, row 4 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, Cu–Hf system (49)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location
Cu10Hf7		-19.2 kJ/mol-atom		DFT			[1] Zhong 2013 cites Ghosh 2007 doi	Table 2, p. 7, row 18 report
Cu10Hf7		-18.73 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 19 report
Cu10Hf7		-16.42 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 20 report
Cu10Hf7	Cu10Hf7	-16 kJ/mol-atom		model	-17.211 (mp-aaacqipw)	-16.705 (oqmd-2052356)	[1] Zhong 2013 cites Turchanin 2008 doi	Table 2, p. 7, row 17 report
Cu10Hf7	Cu10Hf7	-15.5 kJ/mol-atom		model	-17.211 (mp-aaacqipw)	-16.705 (oqmd-2052356)	[1] Zhong 2013 cites Liang 2006 doi	Table 2, p. 7, row 16 report
Cu10Hf7		-15.499 kJ/mol (basis unstated)	298.15	model			[2] Turchanin 2008	Table 2, p. 6, row 11 report
Cu10Hf7		-12.64 kJ/mol (basis unstated) ± 0.49	298.15	experimental			[2] Turchanin 2008 cites ref. 20	Table 2, p. 6, row 9 report
Cu10Hf7	Cu10Hf7	-12.64 kJ/mol-atom	298.15	experimental	-17.211 (mp-aaacqipw)	-16.705 (oqmd-2052356)	[1] Zhong 2013 cites Kleppa 1982 doi	Table 2, p. 7, row 14 report
Cu10Hf7		-4.15 kJ/mol (basis unstated)	298.15	unspecified			[2] Turchanin 2008 cites ref. 13	Table 2, p. 6, row 10 report
Cu10Hf7	Cu10Hf7	-4.15 kJ/mol-atom		model	-17.211 (mp-aaacqipw)	-16.705 (oqmd-2052356)	[1] Zhong 2013 cites Subramanian 1988	Table 2, p. 7, row 15 report
Cu51Hf14	Cu51Hf14	-45.54 kJ/mol-atom	298.15	unspecified	-15.029 (mp-aaacrrua)		[2] Turchanin 2008 cites ref. 13	Table 2, p. 6, row 5 report
Cu51Hf14	Cu51Hf14	-45.54 kJ/mol-atom		model	-15.029 (mp-aaacrrua)		[1] Zhong 2013 cites Subramanian 1988	Table 2, p. 7, row 22 report
Cu51Hf14		-22.9 kJ/mol (basis unstated) ± 2300	298.15	experimental			[2] Turchanin 2008 cites ref. 25	Table 2, p. 6, row 4 report
Cu51Hf14		-16.02 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 26 report
Cu51Hf14		-14.83 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 27 report
Cu51Hf14	Cu51Hf14	-13.65 kJ/mol-atom	298.15	experimental	-15.029 (mp-aaacrrua)		[1] Zhong 2013 cites Kleppa 1982 doi	Table 2, p. 7, row 21 report
Cu51Hf14		-13.65 kJ/mol (basis unstated) ± 240	298.15	experimental			[2] Turchanin 2008 cites ref. 20	Table 2, p. 6, row 3 report
Cu51Hf14	Cu51Hf14	-12.871 kJ/mol-atom	298.15	model	-15.029 (mp-aaacrrua)		[2] Turchanin 2008	Table 2, p. 6, row 6 report
Cu51Hf14	Cu51Hf14	-12.87 kJ/mol-atom		model	-15.029 (mp-aaacrrua)		[1] Zhong 2013 cites Liang 2006 doi	Table 2, p. 7, row 23 report
Cu51Hf14	Cu51Hf14	-12.46 kJ/mol-atom		model	-15.029 (mp-aaacrrua)		[1] Zhong 2013 cites Turchanin 2008 doi	Table 2, p. 7, row 24 report
Cu51Hf14		-7.91 kJ/mol-atom		DFT			[1] Zhong 2013 cites Ghosh 2007 doi	Table 2, p. 7, row 25 report
Cu54Hf14		-7.37 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 28 report
Cu54Hf14		-6.07 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 29 report
Cu5Hf	Cu5Hf	-17.75 kJ/mol-atom		model		-11.585 (oqmd-1373519)	[1] Zhong 2013 cites Subramanian 1988	Table 2, p. 7, row 30 report
Cu5Hf		-17.75 kJ/mol (basis unstated)	298.15	unspecified			[2] Turchanin 2008 cites ref. 13	Table 2, p. 6, row 1 report
Cu5Hf		-12.31 kJ/mol-atom		DFT			[1] Zhong 2013 cites Ghosh 2007 doi	Table 2, p. 7, row 33 report
Cu5Hf		-11.99 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 34 report
Cu5Hf		-11.69 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 35 report
Cu5Hf	Cu5Hf	-9.91 kJ/mol-atom		model		-11.585 (oqmd-1373519)	[1] Zhong 2013 cites Liang 2006 doi	Table 2, p. 7, row 31 report
Cu5Hf		-9.909 kJ/mol (basis unstated)	298.15	model			[2] Turchanin 2008	Table 2, p. 6, row 2 report
Cu5Hf	Cu5Hf	-9.62 kJ/mol-atom		model		-11.585 (oqmd-1373519)	[1] Zhong 2013 cites Turchanin 2008 doi	Table 2, p. 7, row 32 report
Cu8Hf3		-192.72 kJ/mol (basis unstated)	298.15	unspecified			[2] Turchanin 2008 cites ref. 13	Table 2, p. 6, row 7 report
Cu8Hf3	Cu8Hf3	-192.72 kJ/mol-atom		model	-16.068 (mp-aaaaakwv)	-15.567 (oqmd-32345)	[1] Zhong 2013 cites Subramanian 1988	Table 2, p. 7, row 8 report
Cu8Hf3		-17.27 kJ/mol-atom		DFT			[1] Zhong 2013 cites Ghosh 2007 doi	Table 2, p. 7, row 11 report
Cu8Hf3		-16.74 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 12 report
Cu8Hf3		-15.22 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 13 report
Cu8Hf3		-13.629 kJ/mol (basis unstated)	298.15	model			[2] Turchanin 2008	Table 2, p. 6, row 8 report
Cu8Hf3	Cu8Hf3	-13.6 kJ/mol-atom		model	-16.068 (mp-aaaaakwv)	-15.567 (oqmd-32345)	[1] Zhong 2013 cites Liang 2006 doi	Table 2, p. 7, row 9 report
Cu8Hf3	Cu8Hf3	-13.55 kJ/mol-atom		model	-16.068 (mp-aaaaakwv)	-15.567 (oqmd-32345)	[1] Zhong 2013 cites Turchanin 2008 doi	Table 2, p. 7, row 10 report
CuHf2	CuHf2	-56.12 kJ/mol-atom		model	-15.432 (mp-aaaabtgf)	-15.582 (oqmd-1895392)	[1] Zhong 2013 cites Subramanian 1988	Table 2, p. 7, row 2 report
CuHf2		-56.12 kJ/mol (basis unstated)	298.15	unspecified			[2] Turchanin 2008 cites ref. 13	Table 2, p. 6, row 13 report
CuHf2	CuHf2	-20.75 kJ/mol-atom		model	-15.432 (mp-aaaabtgf)	-15.582 (oqmd-1895392)	[1] Zhong 2013 cites Turchanin 2008 doi	Table 2, p. 7, row 4 report
CuHf2		-19.174 kJ/mol (basis unstated)	298.15	model			[2] Turchanin 2008	Table 2, p. 6, row 14 report
CuHf2	CuHf2	-19.17 kJ/mol-atom		model	-15.432 (mp-aaaabtgf)	-15.582 (oqmd-1895392)	[1] Zhong 2013 cites Liang 2006 doi	Table 2, p. 7, row 3 report
CuHf2		-16.36 kJ/mol-atom		DFT			[1] Zhong 2013 cites Ghosh 2007 doi	Table 2, p. 7, row 5 report
CuHf2		-16.22 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 6 report
CuHf2		-15.5 kJ/mol-atom	0	DFT			[1] Zhong 2013	Table 2, p. 7, row 7 report
CuHf2	CuHf2	-15.23 kJ/mol-atom	298.15	experimental	-15.432 (mp-aaaabtgf)	-15.582 (oqmd-1895392)	[1] Zhong 2013 cites Kleppa 1982 doi	Table 2, p. 7, row 1 report
CuHf2		-15.23 kJ/mol (basis unstated) ± 0.5	298.15	experimental			[2] Turchanin 2008 cites ref. 20	Table 2, p. 6, row 12 report

Other properties

Phase transition (11)

Phase transition, Cu–Hf system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	1257.8 K	1257.8	Cu10Hf7 -> liquid Cu10Hf7: Hf 0.411765; liquid: Hf 0.411765	model	[3] Liang 2006	Table 2, p. 3, row 11 report
Phase transition	1298 K	1298	Cu10Hf7 -> liquid Cu10Hf7: Hf 0.411765; liquid: Hf 0.411765	experimental	[3] Liang 2006 cites Subramanian 1988 doi	Table 2, p. 3, row 12 report
Phase transition	1383 K	1383	Cu51Hf14 = liquid Cu51Hf14: Hf 0.215385; liquid: Hf 0.215385	experimental	[1] Zhong 2013 cites Markiv 1974	Table 4, p. 9, row 6 report
Phase transition	1385 K	1385	Cu51Hf14 = liquid Cu51Hf14: Hf 0.215; liquid: Hf 0.215	model	[1] Zhong 2013	Table 4, p. 9, row 5 report
Phase transition	1388 K	1388	Cu51Hf14 -> liquid Cu51Hf14: Hf 0.215385; liquid: Hf 0.215385	experimental	[3] Liang 2006 cites Subramanian 1988 doi	Table 2, p. 3, row 6 report
Phase transition	1388 K	1388	Cu51Hf14 -> liquid Cu51Hf14: Hf 0.215385; liquid: Hf 0.215385	model	[3] Liang 2006	Table 2, p. 3, row 5 report
Phase transition	1583 K	1583	CuHf2 -> liquid CuHf2: Hf 0.666667; liquid: Hf 0.666667	experimental	[3] Liang 2006 cites Markiv 1974	Table 2, p. 3, row 16 report
Phase transition	1583 K	1583	CuHf2 = liquid CuHf2: Hf 0.666667; liquid: Hf 0.666667	experimental	[1] Zhong 2013 cites Markiv 1974	Table 4, p. 9, row 14 report
Phase transition	1583.7 K	1583.7	CuHf2 -> liquid CuHf2: Hf 0.666667; liquid: Hf 0.666667	model	[3] Liang 2006	Table 2, p. 3, row 15 report
Phase transition	1589 K	1589	CuHf2 = liquid CuHf2: Hf 0.667; liquid: Hf 0.667	model	[1] Zhong 2013	Table 4, p. 9, row 13 report
Phase transition	1813.15 K	1813.15	other: bcc -> hcp + liquid	experimental	[3] Liang 2006 cites Pieraggi 1974 doi	p. 2 report	Also, the metatectic decomposition temperature of bcc into hcp and liquid was determined to be 1540 ◦ C.

Formation (5)

Formation, Cu–Hf system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy of formation printed: ΔfS	-2.213 J/mol (basis unstated)/K	298.15	Cu10Hf7 alloy: Hf 0.411765	model	[2] Turchanin 2008	Table 2, p. 6, row 11 report
Entropy of formation printed: ΔfS	-2 J/mol-atom/K	298.15	Cu51Hf14 alloy: Hf 0.215385	model	[2] Turchanin 2008	Table 2, p. 6, row 6 report
Entropy of formation printed: ΔfS	-1.37 J/mol (basis unstated)/K	298.15	Cu5Hf alloy: Hf 0.166667	model	[2] Turchanin 2008	Table 2, p. 6, row 2 report
Entropy of formation printed: ΔfS	-2.028 J/mol (basis unstated)/K	298.15	Cu8Hf3 alloy: Hf 0.272727	model	[2] Turchanin 2008	Table 2, p. 6, row 8 report
Entropy of formation printed: ΔfS	-3.383 J/mol (basis unstated)/K	298.15	CuHf2 alloy: Hf 0.666667	model	[2] Turchanin 2008	Table 2, p. 6, row 14 report

Crystal structure (29)

Crystal structure, Cu–Hf system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a	9.2785 not_printed		Cu10Hf7 alloy: Hf 0.411765	unspecified	[1] Zhong 2013	Table 1, p. 6, row 4 report
Lattice a	11.2319 not_printed		Cu51Hf14 alloy: Hf 0.215385	unspecified	[1] Zhong 2013	Table 1, p. 6, row 2 report
Lattice a	6.873 not_printed		Cu5Hf alloy: Hf 0.166667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 1 report
Lattice a	7.8444 not_printed		Cu8Hf3 alloy: Hf 0.272727	unspecified	[1] Zhong 2013	Table 1, p. 6, row 3 report
Lattice a	3.1631 not_printed		CuHf2 alloy: Hf 0.666667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 5 report
Lattice a	11.18 not_printed	298.15	Cu51Hf14 alloy: Hf 0.215385	experimental	[1] Zhong 2013 cites Gabathuler 1975 doi	Table 1, p. 6, row 6 report
Lattice a	7.8113 not_printed	298.15	Cu8Hf3 alloy: Hf 0.272727	experimental	[1] Zhong 2013 cites Bsenko 1975 doi	Table 1, p. 6, row 7 report
Lattice a	3.1695 not_printed	298.15	CuHf2 alloy: Hf 0.666667	experimental	[1] Zhong 2013 cites Nevitt 1962	Table 1, p. 6, row 8 report
Lattice b	12.6294 not_printed		Cu10Hf7 alloy: Hf 0.411765	unspecified	[1] Zhong 2013	Table 1, p. 6, row 4 report
Lattice b	11.2319 not_printed		Cu51Hf14 alloy: Hf 0.215385	unspecified	[1] Zhong 2013	Table 1, p. 6, row 2 report
Lattice b	6.873 not_printed		Cu5Hf alloy: Hf 0.166667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 1 report
Lattice b	8.1426 not_printed		Cu8Hf3 alloy: Hf 0.272727	unspecified	[1] Zhong 2013	Table 1, p. 6, row 3 report
Lattice b	3.1631 not_printed		CuHf2 alloy: Hf 0.666667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 5 report
Lattice b	11.18 not_printed	298.15	Cu51Hf14 alloy: Hf 0.215385	experimental	[1] Zhong 2013 cites Gabathuler 1975 doi	Table 1, p. 6, row 6 report
Lattice b	8.1014 not_printed	298.15	Cu8Hf3 alloy: Hf 0.272727	experimental	[1] Zhong 2013 cites Bsenko 1975 doi	Table 1, p. 6, row 7 report
Lattice b	3.1695 not_printed	298.15	CuHf2 alloy: Hf 0.666667	experimental	[1] Zhong 2013 cites Nevitt 1962	Table 1, p. 6, row 8 report
Lattice c	9.3148 not_printed		Cu10Hf7 alloy: Hf 0.411765	unspecified	[1] Zhong 2013	Table 1, p. 6, row 4 report
Lattice c	8.2905 not_printed		Cu51Hf14 alloy: Hf 0.215385	unspecified	[1] Zhong 2013	Table 1, p. 6, row 2 report
Lattice c	6.873 not_printed		Cu5Hf alloy: Hf 0.166667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 1 report
Lattice c	9.9788 not_printed		Cu8Hf3 alloy: Hf 0.272727	unspecified	[1] Zhong 2013	Table 1, p. 6, row 3 report
Lattice c	11.134 not_printed		CuHf2 alloy: Hf 0.666667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 5 report
Lattice c	8.235 not_printed	298.15	Cu51Hf14 alloy: Hf 0.215385	experimental	[1] Zhong 2013 cites Gabathuler 1975 doi	Table 1, p. 6, row 6 report
Lattice c	9.947 not_printed	298.15	Cu8Hf3 alloy: Hf 0.272727	experimental	[1] Zhong 2013 cites Bsenko 1975 doi	Table 1, p. 6, row 7 report
Lattice c	11.1333 not_printed	298.15	CuHf2 alloy: Hf 0.666667	experimental	[1] Zhong 2013 cites Nevitt 1962	Table 1, p. 6, row 8 report
lattice volume	16.052 Å3 atom−1		Cu10Hf7 alloy: Hf 0.411765	unspecified	[1] Zhong 2013	Table 1, p. 6, row 4 report
lattice volume	13.935 Å3 atom−1		Cu51Hf14 alloy: Hf 0.215385	unspecified	[1] Zhong 2013	Table 1, p. 6, row 2 report
lattice volume	13.534 Å3 atom−1		Cu5Hf alloy: Hf 0.166667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 1 report
lattice volume	14.486 Å3 atom−1		Cu8Hf3 alloy: Hf 0.272727	unspecified	[1] Zhong 2013	Table 1, p. 6, row 3 report
lattice volume	18.566 Å3 atom−1		CuHf2 alloy: Hf 0.666667	unspecified	[1] Zhong 2013	Table 1, p. 6, row 5 report

Sources

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

Yu Zhong, Arkapol Saengdeejing, Laszlo Kecskes, Bradley Klotz, Zi-Kui Liu, Experimental and computational studies of the Cu–Hf binary system, Acta Materialia 61, 660-669 (2013). doi:10.1016/j.actamat.2012.10.014
M. A. Turchanin, P. G. Agraval, Thermodynamic assessment of the copper-hafnium system, Powder Metall Met Ceram 47, 223-233 (2008). doi:10.1007/s11106-008-9008-4
Dong Liang, Yajun Liu, Reevaluation of the Cu–Hf binary system, Journal of Alloys and Compounds 426, 101-105 (2006). doi:10.1016/j.jallcom.2006.02.013

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-Diagrams: calculated binary phase diagrams (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735859
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); 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; 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). 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_phase_diagrams_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Diagrams: calculated binary phase diagrams}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735859},
  url       = {https://doi.org/10.5281/zenodo.23735859}
}

@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}
}