Neodymium doped gadolinium gallium oxide （Nd：GGG） nanopowders synthesized by microwave gel combustion using alanine as a fuel was reported. Metal nitrates solution with alanine fuel was combusted in microwave to gi...Neodymium doped gadolinium gallium oxide （Nd：GGG） nanopowders synthesized by microwave gel combustion using alanine as a fuel was reported. Metal nitrates solution with alanine fuel was combusted in microwave to give precursor. The micro-wave precursor powder was calcined at different temperatures from 800 to 1100 ℃. Phase pure Nd：GGG formation took place at 800 to 1100 ℃ as observed by X-ray diffraction （XRD） and Fourier transform infra-red （FTIR） spectroscopy. However particle size in-creased with calcinations temperature from 25 nm at 800 ℃ to 200 nm at 1100 ℃.Nd：GGG nanopowder obtained at different calci-nation temperatures were compacted and sintered at 1550 ℃ for 3 h in air. Most densified ceramic was obtained from Nd：GGG nanopowder calcined at 1100 ℃. Microstructure as observed from scanning electron microscopy （SEM） showed that the most densi-fied ceramic, obtained from nanopowder calcined at a higher calcination temperature, had a more uniform grain-size distribution, fewer pores and greater densification. XRD of sintered sample showed retention of phase purity.展开更多
Solution combustion synthesis of single-phase gadolinium gallium oxide （Gd3GasO12, GGG） nanopowders, by a fuel mixture approach using urea and glycine at a low temperature of 500 ℃, was being reported for the first...Solution combustion synthesis of single-phase gadolinium gallium oxide （Gd3GasO12, GGG） nanopowders, by a fuel mixture approach using urea and glycine at a low temperature of 500 ℃, was being reported for the first time. Based on the fact that urea and glycine are good fuels for gallium oxide and gadolinium oxide synthesis, the fuel mixture composition was obtained, which could lead to direct phase pure cubic Gd3Ga5O12 formation without any subsequent calcination step. Combustion was carried out in furnace pre-heated at 500 ℃. Thermogravimetric analysis （TGA） of combustion product showed negligible mass loss indicating direct formation of GGG powder. Fourier transform infrared （FTIR） spectrum of combusted product showed peak characteristic of GGG in case of mixed fuel. X-ray diffraction （XRD） confirmed formation of phase pure GGG at 500 ℃ in preheated furnace. Very fine, well dispersed nanometric particles of size range of 50-100 nm were obtained, being uniform and close to spherical morphology as observed by transmission electron microscope （TEM）.展开更多
基金Laser Science and Technology Centre, Defence Research and Development Organization (DRDO), Delhi for his encouragement and support to carry out this work
文摘Neodymium doped gadolinium gallium oxide （Nd：GGG） nanopowders synthesized by microwave gel combustion using alanine as a fuel was reported. Metal nitrates solution with alanine fuel was combusted in microwave to give precursor. The micro-wave precursor powder was calcined at different temperatures from 800 to 1100 ℃. Phase pure Nd：GGG formation took place at 800 to 1100 ℃ as observed by X-ray diffraction （XRD） and Fourier transform infra-red （FTIR） spectroscopy. However particle size in-creased with calcinations temperature from 25 nm at 800 ℃ to 200 nm at 1100 ℃.Nd：GGG nanopowder obtained at different calci-nation temperatures were compacted and sintered at 1550 ℃ for 3 h in air. Most densified ceramic was obtained from Nd：GGG nanopowder calcined at 1100 ℃. Microstructure as observed from scanning electron microscopy （SEM） showed that the most densi-fied ceramic, obtained from nanopowder calcined at a higher calcination temperature, had a more uniform grain-size distribution, fewer pores and greater densification. XRD of sintered sample showed retention of phase purity.
文摘Solution combustion synthesis of single-phase gadolinium gallium oxide （Gd3GasO12, GGG） nanopowders, by a fuel mixture approach using urea and glycine at a low temperature of 500 ℃, was being reported for the first time. Based on the fact that urea and glycine are good fuels for gallium oxide and gadolinium oxide synthesis, the fuel mixture composition was obtained, which could lead to direct phase pure cubic Gd3Ga5O12 formation without any subsequent calcination step. Combustion was carried out in furnace pre-heated at 500 ℃. Thermogravimetric analysis （TGA） of combustion product showed negligible mass loss indicating direct formation of GGG powder. Fourier transform infrared （FTIR） spectrum of combusted product showed peak characteristic of GGG in case of mixed fuel. X-ray diffraction （XRD） confirmed formation of phase pure GGG at 500 ℃ in preheated furnace. Very fine, well dispersed nanometric particles of size range of 50-100 nm were obtained, being uniform and close to spherical morphology as observed by transmission electron microscope （TEM）.
