RIBEIRO, M.A.; RIBEIRO, Maria Aparecida.
Resumo:
Developing methods suitable for the production of ceramic powders ha bccn of
great relevancc loday. sincc lhe important propertics in cerami c depend large ly on lhe
unique charactcristics of the powder used. Thcse cbaracteristics are affectcd by lhe
method used to gene rate the powder. For applicalions that require high perfom1ance and
lügh technology. such as thc clectronics industry, where more sophisticated ceramic
powders are desirable, the way to obtain the powder must ensure high purity,
reproduciblc and controlled chcmical compo ition. atomic uniformity and sma ll particle
size. Based in this context. we propose the synthesis and structural characterization of
powders and films of pure ZnO and doped with coba lt (Co2
+) with concentration of
0.025 to 0. 1 moles synthcsized by Pechini mcthod for futurc application in as optical
material . Characterizations b) X-ray diffraction. textura! analy is by 2 from the BET
method, scanning electron microscop) analy is and thennogra\ imctry (TG) were
performed. The compositions with values of 0.05; 0.075 and 0. 1 moles of cobah showed
the presence of the second phase of cobalt oxide (Co203) and the desired phase of ZnO.
According to the results. onl y the composition \\ ith concentration of 0.025 moles of
cobalt presented a monophasic phase. o. it was cho en this last composition for the
production of thi n films. The result of X-ray di ITraction for the ftlm doped with 0.025
moles of Co showed that this structure is a typical hexagonal wurtzite. The analysis of
AFM showed that the conccntration of Co do not influence the microstructure of thin
films. which shO\\Cd spherical grains. The tran mission spectrum showed a we ll defi ned
gap close to 4.8 cV. Measurcs of diffuse re tlcctancc of thin films shov.'ed th.ree peaks of
ernissions: a band of the absorption around 590 11111 . a band close to 51 O nrn, and another
at 650 nrn. which are respon iblc for the green color of thin films. The thin filrns of ZnO
doped with coball and synthesizcd by Pechini melhod. ha\'e application as attenuators in
lhe visible and near infrared rcgions. Moreover. thcy can be used a V filters.
