Y2Hf2O7

Yttrium hafnate · YHO

Yttrium hafnate is a stable, insulating oxide-ion conductor used in high-temperature materials and protective coatings.

Crystal structure of Y2Hf2O7 (cubic, Fd-3m (No. 227))
Ground-state structure · Materials Project
Overview

About Yttrium hafnate

Yttrium hafnate is a thermodynamically stable oxide that crystallizes in a fluorite-related structure. As a wide-band-gap insulator, it exhibits excellent chemical and structural integrity, making it a robust candidate for high-temperature environments where ionic conductivity and thermal stability are required.

This compound is primarily utilized in advanced materials science for its ability to withstand extreme conditions. Its role as an oxide-ion conductor is highly valued in the development of protective coatings and electrolyte components, where its structural reliability ensures long-term performance in demanding industrial applications.

At a glance

Key Properties

Cross-validated computational properties for Yttrium hafnate, aggregated across 3 databases.

Band Gap

3.46–4.43 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

11
3 databases, 3 space groups
Crystallography

Reported Structures

Lowest-energy structures reported for Y2Hf2O7, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
Fd-3m (No. 227)cubic3.460.0003-10.1327.57
C2/m (No. 12)monoclinic4.430.0472-10.0855.90
P41212 (No. 92)tetragonal4.400.0762-10.0566.41
C2/m (No. 12)Monoclinic5.90
C2/m (No. 12)Monoclinic6.26
C2/m (No. 12)Monoclinic6.04
C2/m (No. 12)
Fd-3m (No. 227)Cubic7.85
Fd-3m (No. 227)
Fd-3m (No. 227)Cubic7.37
Fd-3m (No. 227)Cubic7.56
Uses

Applications

Where Yttrium hafnate is used.

Thermal barrier coatingsSolid oxide fuel cell electrolytesHigh-temperature structural ceramics
Reference

Frequently Asked Questions

Common questions about Yttrium hafnate, answered from cross-validated data.

What is Y2Hf2O7?

Yttrium hafnate is a stable, insulating oxide-ion conductor used in high-temperature materials and protective coatings.

More questions
What is Y2Hf2O7 used for?
Yttrium hafnate (Y2Hf2O7) is used in thermal barrier coatings, solid oxide fuel cell electrolytes, and high-temperature structural ceramics.
What is the band gap of Y2Hf2O7?
Yttrium hafnate (Y2Hf2O7) has a DFT-computed band gap of 3.46–4.43 eV across 11 reported structures.
Is Y2Hf2O7 a metal, semiconductor, or insulator?
With a wide band gap up to 4.43 eV it is an insulator / wide-band-gap material.
Is Y2Hf2O7 thermodynamically stable?
Yes — Yttrium hafnate (Y2Hf2O7) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of Y2Hf2O7?
The lowest-energy reported polymorph of Yttrium hafnate (Y2Hf2O7) is cubic symmetry, space group Fd-3m (No. 227).
What is the density of Y2Hf2O7?
The computed density of the ground-state structure of Yttrium hafnate (Y2Hf2O7) is 7.57 g/cm³.
How many polymorphs of Y2Hf2O7 are known?
11 structures of Y2Hf2O7 are reported across 3 databases, spanning 3 distinct space groups.
What elements does Y2Hf2O7 contain?
Yttrium hafnate (Y2Hf2O7) contains Hf, O, and Y (3 elements).
Where does the data for Y2Hf2O7 come from?
Y2Hf2O7 data is cross-referenced from materials_project, mpaloe, jarvis.
Comparison

How It Compares

Within the fluorite oxide-ion conductors class.

Within the family of fluorite oxide-ion conductors, Yttrium hafnate stands out for its exceptional stability compared to counterparts like Y2Zr2O7. While many zirconate-based members of this class are widely studied for their ionic transport properties, the hafnate variant provides a distinct alternative that often offers superior thermal resistance, positioning it as a critical material for high-performance engineering tasks.

Explore

Related Compounds

Other Fluorite Oxide-Ion Conductors in the database.

Data sources & attribution
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • mpaloe — Data from mpaloe.
  • jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).

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