Characterization of the piezochromic behavior of some members of the CuMo1-xWxO4 series
Language
en
Article de revue
This item was published in
Inorganic Chemistry. 2008, vol. 47, n° 7, p. 2404-2410
American Chemical Society
English Abstract
The members of the CuMo1−xWxO4 series (0 ≤ x < 0.1) undergo a first-order phase transition that can be induced by pressure application; the thermochromic properties of such a series have already been reported. The two ...Read more >
The members of the CuMo1−xWxO4 series (0 ≤ x < 0.1) undergo a first-order phase transition that can be induced by pressure application; the thermochromic properties of such a series have already been reported. The two polymorphic forms exhibit two distinguishable colors: green for the low pressure form (α) and brownish-red for the high pressure one (γ). These oxides can open up a new market for friendly pressure indicators, particularly for the compositions (0.07 ≤ x ≤ 0.1) for which the two polymorphs are stable at room temperature, that is, for which the color transition via pressure application is nonreversible. Within the CuMo1−xWxO4 solid solution domain, the dependence of the transition pressure versus tungsten content, temperature of measurement, and sample thermal-pressure history was studied. A large control of the transition pressure (from 5 to several 100 MPa) was brought to the fore. The transition was then studied using X-ray diffraction and transmission electron microscopy-energy dispersive X-ray analyses. This first-order transition, occurring by atomic migration inside the cell, seems to be preceded by an atomic disordering; moreover, transition temperatures may be modified by W segregation at the surface of the grains.Read less <
English Keywords
Inorganic comounds
Solid solution
Piezochromism
X-ray diffraction
Transmission eletron microscopy
Inorganic comounds
Origin
Hal imported