Rare-earth ferrite garnet is one of the most important materials applied in microwave transducer and in- frared magneto-optical devices, etc. Nd3-xAExFe5O12（AE=Ca, Sr） crystals, which have cubic structure with the s...Rare-earth ferrite garnet is one of the most important materials applied in microwave transducer and in- frared magneto-optical devices, etc. Nd3-xAExFe5O12（AE=Ca, Sr） crystals, which have cubic structure with the space group ofIa-3 d and lattice constants over 1.26 nm, were prepared via the mild hydrothermal method. The structural, morhpology and magnetic properties were characterized by means of powder X-ray diffraction, scanning electronic microscopy, as well as vibrating sample magnetometer and M6ssbauer spectroscopy, respectively. M6ssbaner spectroscopy demonstrates the coexistence of Sr2＋, Ca2＋ and Nd3＋ at the C sites of the dodecahedrons for different substituted garnets. The crystal shape is dodecahedron, and the particle sizes are decreased with increasing the Ca and Sr doping concentrations. By recording the magnetic hysteresis loops and M-T curves at different temperatures, it can be seen that with the increasing x, the saturation magnetization values decrease while the coercive forces increase under the condition of high temperatures.展开更多
Ca3Sc2Si3O12:Ce3+ phosphors with single-phase were successfully synthesized by a gel-combustion method.Annealing atmosphere greatly affected the luminescent properties of the phosphor.The intensity of absorption band ...Ca3Sc2Si3O12:Ce3+ phosphors with single-phase were successfully synthesized by a gel-combustion method.Annealing atmosphere greatly affected the luminescent properties of the phosphor.The intensity of absorption band at 450 nm was greatly increased with a reducing atmosphere,which was very suitable as a color converter in white LED.The absorption at 243 and 311 nm was gradually enhanced with a stronger reducing atmosphere and a new absorption peak at 362 nm appeared in N2+H2 mixing gas.The emission intensit...展开更多
文摘Rare-earth ferrite garnet is one of the most important materials applied in microwave transducer and in- frared magneto-optical devices, etc. Nd3-xAExFe5O12（AE=Ca, Sr） crystals, which have cubic structure with the space group ofIa-3 d and lattice constants over 1.26 nm, were prepared via the mild hydrothermal method. The structural, morhpology and magnetic properties were characterized by means of powder X-ray diffraction, scanning electronic microscopy, as well as vibrating sample magnetometer and M6ssbauer spectroscopy, respectively. M6ssbaner spectroscopy demonstrates the coexistence of Sr2＋, Ca2＋ and Nd3＋ at the C sites of the dodecahedrons for different substituted garnets. The crystal shape is dodecahedron, and the particle sizes are decreased with increasing the Ca and Sr doping concentrations. By recording the magnetic hysteresis loops and M-T curves at different temperatures, it can be seen that with the increasing x, the saturation magnetization values decrease while the coercive forces increase under the condition of high temperatures.
基金supported by the Ministry of Science and Technology of China (2006CB601104,2006AA03A133)
文摘Ca3Sc2Si3O12:Ce3+ phosphors with single-phase were successfully synthesized by a gel-combustion method.Annealing atmosphere greatly affected the luminescent properties of the phosphor.The intensity of absorption band at 450 nm was greatly increased with a reducing atmosphere,which was very suitable as a color converter in white LED.The absorption at 243 and 311 nm was gradually enhanced with a stronger reducing atmosphere and a new absorption peak at 362 nm appeared in N2+H2 mixing gas.The emission intensit...
