YPO4
xenotime · yttrium orthophosphate
YPO4 is a stable, insulating yttrium-based phosphate commonly used as a host material for optical and luminescent applications.
About xenotime
YPO4 is a robust inorganic compound that functions as a wide-band-gap insulator. Its high thermodynamic stability makes it a reliable host lattice for various dopants, particularly in the field of photonics and luminescence research.
Due to its structural integrity and chemical durability, this material is frequently utilized in high-performance optical devices. Its ability to accommodate rare-earth ions within its crystal framework allows for the development of specialized phosphors and laser host materials.
Key Properties
Cross-validated computational properties for xenotime, aggregated across 3 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of YPO4. Tight agreement means computed properties can be trusted without re-running calculations.
Agreement ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
Reported Structures
Lowest-energy structures reported for YPO4, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| — | — | 6.23 | 0.0000 | -3.344 | — |
| I41/amd (No. 141) | tetragonal | 6.01 | 0.0000 | -3.213 | — |
| I41/amd (No. 141) | tetragonal | 5.81 | 0.0000 | -8.763 | 4.27 |
| — | — | 6.11 | 0.0207 | -3.323 | — |
| P6222 (No. 180) | hexagonal | 5.37 | 0.0288 | -8.734 | 3.47 |
| — | — | 5.92 | 0.0452 | -3.299 | — |
| — | — | 4.81 | 0.0821 | -3.262 | — |
| — | — | 0.00 | 0.0824 | -3.262 | — |
| — | — | 4.66 | 0.1176 | -3.226 | — |
| — | — | 5.17 | 0.1190 | -3.225 | — |
| — | — | 5.99 | 0.1289 | -3.215 | — |
| — | — | 4.84 | 0.1598 | -3.184 | — |
Synthesis Routes
Literature-extracted synthesis procedures targeting YPO4.
Applications
Where xenotime is used.
Frequently Asked Questions
Common questions about xenotime, answered from cross-validated data.
What is YPO4?
YPO4 is a stable, insulating yttrium-based phosphate commonly used as a host material for optical and luminescent applications.
What is YPO4 used for?
What is the band gap of YPO4?
Is YPO4 a metal, semiconductor, or insulator?
Is YPO4 thermodynamically stable?
What is the crystal structure of YPO4?
How many polymorphs of YPO4 are known?
How is YPO4 synthesized?
What elements does YPO4 contain?
Where does the data for YPO4 come from?
How It Compares
As a highly stable orthophosphate, YPO4 serves as a foundational reference point for studying structural motifs in complex oxide systems. It is widely recognized for its structural versatility, appearing in multiple distinct phases that facilitate its use in diverse technological environments.
Data sources & attribution
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
- mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.
- cod — Data from the Crystallography Open Database (crystallography.net/cod/). Cite: Grazulis et al., J. Appl. Cryst. 42, 726 (2009). (CC0-1.0)
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