Yttria

Crystal structure
__ Y 3+      __ O 2−
Crystal system	cubic
Space group	Ia 3 (No. 206)
Lattice parameters	a = 926.84 pm
General
Surname	Yttria
other names	Yttrium (III) oxide Yttrium sesquioxide
Ratio formula	Y 2 O 3
Brief description	white, odorless solid
External identifiers / databases
CAS number 1314-36-9 EC number 215-233-5 ECHA InfoCard 100,013,849 PubChem 159374 Wikidata Q414685
properties
Molar mass	225.81 g mol −1
Physical state	firmly
density	5.01 g cm −3
Melting point	2410 ° C
boiling point	4300 ° C
solubility	almost insoluble in water moderately soluble in strong mineral acids
Refractive index	1.930
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Yttrium oxide is a chemical compound , more precisely the oxide of yttrium . It is thermodynamically very stable and resistant to many reactive metal melts such as titanium or uranium .

Occurrence

Yttrium oxide occurs naturally as a component in various yttrium minerals ( samarskite , yttrobetafit ).

Extraction and presentation

Yttrium oxide is technically made by calcining z. B. yttrium oxalate obtained in the air.

${\displaystyle \mathrm {2\ Y_{2}(C_{2}O_{4})_{3}+3\ O_{2}\longrightarrow 2\ Y_{2}O_{3}+12\ CO_{2}} }$

properties

Yttrium oxide has a refractive index of 1.930 and a cubic crystal structure in the C oxide type of the lanthanoids ( space group Ia 3 (space group no. 206) , lattice parameter a = 10.12 Å ).

use

Yttria is used:

• as a connection for high temperature-resistant applications (e.g. as a coating material for graphite in nuclear technology)
• as a sintering aid for ceramic materials
• used to stabilize zirconium (IV) oxide (e.g. for lambda probes or in dental technology)
• Uranium oxide diluent for fuel rods (forms a solid solution with uranium oxide)
• for the production of yttrium and other yttrium compounds
• for optical coatings
• as a raw material for high temperature superconductors ( YBCO )
• as a raw material for (red) luminophores for CRT screens
• together with thorium dioxide to produce IR and UV light permeable glass
• YInMn blue is a mixed oxide of yttrium, indium and manganese oxides, which shows a very pure and brilliant blue

Individual evidence

1. ↑ ^{a b c d e f} Entry on yttrium (III) oxide in the GESTIS substance database of the IFA , accessed on December 19, 2019(JavaScript required) .
2. ↑ Yttrium Oxide (AmericanElements)
3. ↑ ^{a b} David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Crystals, pp. 10-248.
4. ↑ M. Marezio: Refinement of the crystal structure of In ₂ O ₃ at two wavelengths , in: Acta Cryst , 1966 , 20 , pp. 723-728; doi: 10.1107 / S0365110X66001749 .
5. ↑ Export list 110th ÄVO ( Memento of December 8, 2012 in the Internet Archive ) (PDF; 156 kB)
6. ↑ vias.org: Lambda probe
7. ↑ AGC Galvanotechnik ( Memento from June 8, 2009 in the Internet Archive )
8. ↑ Coating materials for the optical industry. In: gfe.com. Society for Electrometallurgy, accessed on January 3, 2018 .