Trivalent cerium-ion-doped Y3(Al, Ga)5O12 nanoparticle phosphor nanoparticles were synthesized using the reversemicelle process. The Ce doped Y3(Al, Ga)5O12 particles were obtained from nitrate solutions dispersed in the nanosized aqueousdomains of a micro emulsion consisting of cyclohexane as the oil phase and poly(oxyethylene) nonylphenyl ether (Igepal CO-520) as the non-ionic surfactant. The crystallinity, morphology, and thermal properties of the synthesized Y3(Al, Ga)5O12:Ce3+powders were characterized by thermogravimetry-differential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD),scanning electron microscopy (SEM), and transmission electron microscopy. The crystallinity, morphology, and chemical statesof the ions were characterized; the photo-physical properties were studied by taking absorption, excitation, and emission spectrafor various concentrations of cerium. The photo physical properties of the synthesized Y3(Al, Ga)5O12:Ce3+ powders werestudied by taking the excitation and emission spectra for various concentrations of cerium. The average particle size of thesynthesized YAG powders was below 1µm. Excitation spectra of the Y3Al5O12 and Y3Al3.97Ga1.03O12 samples were 485nmand 475nm, respectively. The emission spectra of the Y3Al5O12 and Y3Al3.97Ga1.03O12 were around 560nm and 545nm,respectively. Y3(Al, Ga)5O12:Ce3+ is a red-emitting phosphor; it has a high efficiency for operation under near UV excitation,and may be a promising candidate for photonic applications.

A preparation of NixMn1-xFe2O4 nanoparticles produced via the reduction of Nickel nitrate hexahydrate, Manganese (II) nitrate hexahydrate and Iron nitrate nonahydrate with hydrazine in Igepal CO-520/cyclohexane reverse micelle solutions was investigated. Transmission Electron Microscope (TEM), X-ray Diffraction (XRD) and Vibration Sample Magnetometer (VSM) analyses showed that the resultant nanoparticles increased the molar ration of water to Igepal CO-520 as the concentrations of Nickel nitrate hexahyrate, Manganese (II) nitrate hexahydrate and Iron nitrate nonahydrate increased. The average size of the synthesized particles calcined at 600˚C for 2hrs was in the range of 20 nm to 30 nm, and the particle distribution was broadened. The phase of the synthesized particles was crystalline, and the magnetic behavior of the synthesized particles was superparamagnetism. The effect of the synthesis parameters of the molar ratio of water to surfactant and the calcination temperature was discussed.