3篇
您的检索式：作者名="M.R.D.BOMIO"
|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Influence of variables on the synthesis of CoFe_(2)O_(4)pigment by the complex polymerization method显示文摘Synthetic inorganic pigments are most widely used in ceramic applications due to their excellent chemical and thermal stability and their lower toxicity to both human and environment as well.In the present work,black ceramic pigment CoFe_(2)O_(4)has been synthesized by the complex polymerization method(CPM)with good chemical homogeneity.In order to study the influence of variables on the process of obtaining pigment through CPM,2^((5-2))fractional factorial design with resolution III was used.The variables studied in the mathematical modeling were:citric acid/metal concentration,pre-calcination time,calcination temperature,calcination time,and calcination rate.Powder pigments were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and UV-visible(UV-Vis)spectroscopy.Based on the results,the formation of cobalt ferrite phase(CoFe_(2)O_(4))with spinel structure was verified.The color of pigments obtained showed dark shades,from black to gray.The model adjusted to the conditions proposed in this study due to the determination coefficient of 99.9%and variance(R²)showed that all factors are significant at the confidence level of 95%. | P.N.MEDEIROS Y.F.GOMES M.R.D.BOMIO I.M.G.SANTOS M.R.S.SILVA C.A.PASKOCIMAS M.S.LI F.V.MOTTA | 2015 | Journal of Advanced Ceramics2015，4，2： | 0 |
| 2 | Effect of different starting materials on the synthesis of Ba_(0.8)Ca_(0.2)TiO_(3)显示文摘Literature has reported the synthesis of barium calcium titanates by various synthesis methods such as solid state reaction,co-precipitation and polymer precursors.These compounds are usually obtained using calcium carbonate(CaCO_(3)),barium carbonate(BaCO3)and titanium oxide as starting materials.This study investigated the effect of different starting reagents on the synthesis of Ba_(0.8)Ca_(0.2)TiO_(3)(BCT)by complex polymerization method(CPM).Two sets of starting precursors were used:titanium citrate,CaCO_(3)and BaCO3,and titanium citrate and Ba1-xCaxCO3 solid solution precursor.Samples were crystallized at a temperature range from 400℃to 700℃for different time.The obtained powders were characterized by X-ray diffraction(XRD),thermogravimetry(TG)and differential thermal analysis(DTA),and Raman and infrared spectroscopy.The infrared spectroscopy indicated that the chelation processes of Ba,Ca,Ti and CA ions are very similar.The results showed that the use of CaCO_(3)and BaCO3 or Ba1-xCaxCO3 solid solution as precursors does not affect the final properties of BCT powders obtained by CPM. | P.N.MEDEIROS V.D.ARAÚJO A.P.A.MARQUES R.L.TRANQUILIN C.A.PASKOCIMAS M.R.D.BOMIO J.A.VARELA E.LONGO F.V.MOTTA | 2015 | Journal of Advanced Ceramics2015，4，1： | 0 |
| 3 | Red-emitting CaWO4:Eu^(3+),Tm^(3+)phosphor for solid-state lighting:Luminescent properties and morphology evolution显示文摘CaWO_(4):xEu^(3+),yTm^(3+)crystals were obtained by facile synthesis at low temperature by the microwaveassisted hydrothermal method(MAH).The phase formation,morphology,luminescent properties and ene rgy transfer were investigated.The X-ray diffraction(XRD)re sults show the formation of a scheelitelike tetragonal structure without the presence of secondary phases.The growth mechanism of hierarchical micro structures based on self-assembly and Ostwald-ripening processes was evaluated,obtaining different types of morphologies.The luminescence spectra of CaWO_(4):Eu^(3+),Tm^(3+)at 325 nm excitation show the predominance of red emission at the 5 D0→7 F2(Eu^(3+))transition at 624 nm.This feature signals dominant behavior of the electric dipole type.The presence of Tm^(3+)is notably evident in the absorption spectra by the related excitation transitions:3 H6→1 G4,3 H6→3 F3 and 3 H6→3 H4.Color parameters are discussed to characterize CaWO_(4):Eu^(3+),Tm^(3+)emission.The study of the emission spectrum as a function of the concentration of Eu^(3+)(x mol%)and Tm^(3+)(y mol%)indicates that the CaWO_(4):Eu^(3+),Tm^(3+)phosphors show stronger red emission intensity and exhibit the CIE value of x=0.63 and y=0.35.The photoluminescence results show 97%high color purity for CaWO_(4):4 mol%Eu^(3+),a high CRI(92%)and a low CCT of 1085 K.These results demonstrate that the CaWO_(4):Eu^(3+),Tm^(3+)red phosphors are promising as color converters for application in white light-emitting diodes and display devices. | L.X.Lovisa I.M.P.da Silva A.A.G.Santiago M.Siu Li E.Longo C.A.Paskocimas M.R.D.Bomio F.V.Motta | 2022 | Journal of Rare Earths2022，40，2： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员