M. Gasgnier et al., MICROWAVE-MONOMODE ENERGY-TRANSFER - CHEMICAL SYNTHESES, CRYSTALLOGRAPHIC AND THERMAL-PROPERTIES OF MINERAL POWDERS, Materials research bulletin, 31(9), 1996, pp. 1101-1109
The high energy transfer produced by means of the electromagnetic beam
of microwave apparatus is used more and more to carry out chemical sy
ntheses of numerous chemical compounds. This paper draws particular at
tention to the formation of metals, viz. copper and silver, and carbid
es, viz. TaC, carried out at ambient atmosphere. The monomode techniqu
e is highly available; in this case, the beam was nearly focused at th
e center of the test tube containing the powder. The compounds copper
hemioxide, copper hemisulfide, tantalum pentoxide, titanium dioxides (
anatase and rutile), palladium black powder, and mixed vanadium pentox
ide and zirconium dioxide were studied. The crystallographic structure
s of these materials were systematically determined by X-ray diffracti
on before and after treatment. A scanning electron micrograph is given
for copper metal, and the value of the dielectric absorption paramete
r is evaluated for silver oxide and sulfide. The measurement of temper
ature in the case of incandescent red powders is addressed, because it
leads to various controversies.