Zirconium tungstate

Crystal structure
green octahedron: ZrO 6 ; red tetrahedra: WO 4 ; red spheres: oxygen atoms
General
Surname	Zirconium tungstate
other names	Zirconium tungstate
Ratio formula	Zr (WO 4 ) 2
Brief description	white odorless powder
External identifiers / databases
CAS number 16853-74-0 EC number 240-876-3 ECHA InfoCard 100.037.145 Wikidata Q205661
properties
Molar mass	586.92 g mol −1
Physical state	firmly
density	5.1 g cm −3
solubility	almost insoluble in water
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 .

Zirconium tungstate (Zr [WO ₄ ] ₂ ) is a chemical compound of zirconium , tungsten and oxygen and thus a compound from the group of tungstates .

Extraction and presentation

Zirconium tungstate can be obtained by reacting zirconium (IV) oxide and tungsten (VI) oxide .

${\displaystyle \mathrm {ZrO_{2}+2\ WO_{3}\longrightarrow {}\ Zr(WO_{4})_{2}} }$

properties

A very characteristic peculiarity of zirconium tungstate is the density anomaly . It contracts when heated, unlike most other substances. This behavior occurs between −270  ° C (3.15  Kelvin ) and 777 ° C, the linear expansion is −8.7 · 10 ⁻⁶  K ⁻¹ . Some other materials have such a “reverse” temperature behavior, but they show it within a much smaller temperature range.

application

As a filler, it can partially or completely compensate for the positive temperature expansion of a matrix material, which results in materials with low thermal expansion.

Individual evidence

1. ↑ ^{a b c d e} data sheet zirconium tungstate from AlfaAesar, accessed on December 26, 2019 ( PDF )(JavaScript required) .
2. ↑ Solid body with negative thermal expansion
3. ↑ Wayne Weyer et al .: Achieving Dimensional Stability Using Functional Fillers , Conference Paper 46th AIAA / ASME / ASCE / AHS / ASC Structures, Structural Dynamics and Materials Conference, doi : 10.2514 / 6.2005-2091 .