Table 3 Thermodynamic data for cubic and liquid HfO₂.

T (T-C) trs, °C

2530

Experimental best value^†

WZA 2006⁶

T-C ΔV, %

0.87 ± 0.08

HT XRD Experiment^†

This work

Density, g/cm³

9.68–9.58

XRD at (2530–2800 °C)^†

This work

9.74–9.65

Ab initio MD at 2527–2727 °C

This work

C_p, J/mol/K

126 ± 4

Ab initio MD at 2527–2727 °C

This work

Linear TEC, α, K⁻¹

(1.3 ± 0.4) ·10⁻⁵

HT XRD at (2530–2800 °C)^†

This work

Vol. TEC, α_v, K⁻¹

(4 ± 1) 10⁻⁵

HT XRD at (2311–2710 °C)^†

This work

(5.0 ± 0.7) ·10⁻⁵

Ab initio MD at 2527–2727 °C

This work

T_mlt, °C

2800

Experiment best value

WZA 2006⁶

ΔV on melting, %

10 ± 2

Ab initio MD

This work

ΔH_fus, kJ/mol

89.6

Assessed ΔS·T_m

WZA 2006⁶

61 ± 10

DnC experiment

This work

52 ± 2

Ab initio MD

This work

ΔS_fus, J/mol/K

29

Assessed from ZrO₂ data

WZA 2006⁶

20

Experiment ΔH/T_m (K)

This work

17

Ab initio MD ΔH/T_m (K)

This work

Density Liq, g/cm³

8.73–8.53

Ab initio MD at 2827–3127 °C

This work

8.16

PDF experiment

Gallington 2017¹⁰

C_p Liq, J/mol/K

109 ± 15

Ab initio MD at 2727–3127 °C

This work

Vol. TEC, α_v, K⁻¹

(8 ± 1)·10⁻⁵

Ab initio MD at 2827–3127 °C

This work