Natural scapolite including the S-2impurity is a typical silicate luminescent mineral.According to the formation conditions and chemical composition of natural scapolite,we synthesized Na_(4)Ca_(4)Al_(6)Si_(9)O_(24)(s...Natural scapolite including the S-2impurity is a typical silicate luminescent mineral.According to the formation conditions and chemical composition of natural scapolite,we synthesized Na_(4)Ca_(4)Al_(6)Si_(9)O_(24)(scapolite)by the high temperature solid-phase reaction,and prepared the synthetic scapolite phosphors activated with Ce^3+and Tb^3+.The photoluminescence(PL)properties of the obtained phosphors were studied.The results indicated that the PL intensity of green(545nm)emission corresponding to the 5 D4→7 F5 transition within Tb^3+in the Ce^3+,Tb^3+-codoped samples was much higher than that of the Tb^3+-doped samples.The PL properties of the samples activated with various Ce^3+concentrations were measured,and their fluorescence lifetime and energy transfer mechanism were analyzed.We proved that there was energy transfer from Ce^3+to Tb^3+,and the energy transfer efficiency was at its maximum when the Ce^3+to Tb^3+mass ratio was 0.02∶0.03.Upon measurement by chromaticity coordinates,we found that the luminescence of the samples could be adjusted in the green area with varying Ce^3+concentrations.We thus deem that scapolite phosphors Na4Ca4Al6Si9O24∶Ce^3+,Tb^3+are promising to become the new white LED phosphors.展开更多
Pasveh gabbros are mafic component of a plutonic complex in the northwest Sanandaj- Sirjan Zone. These cumulative rocks are composed of plagioclase and calcic clinopyroxene （Cpx）, which yield unusually high CaO （〉...Pasveh gabbros are mafic component of a plutonic complex in the northwest Sanandaj- Sirjan Zone. These cumulative rocks are composed of plagioclase and calcic clinopyroxene （Cpx）, which yield unusually high CaO （〉19 wt.%） in whole-rock chemistry. Petrographical and geochemical data suggest that Pasveh gabbros can be divided into two groups： free scapolite and scapolite-bearing gabbros. The second group has higher Na20, K20, and P205 relative to free scapolite ones and is enriched in LIL （large ion lithophile） and HFS （high field strength） elements. Two stages of metasomatism affected the primary composition of mafic rocks. Firstly, high temperature reaction caused to invert primary high Ti clinopyroxene to low Ti cUnopyroxene＋high Ti amphibole. This reaction was extensive and included all gabbroic samples. Hydrothermal fluids involved in this process can be derived from dehydration reactions of country rocks or from other magmas incorporated in the formation of Pasveh complex pluton. The second metasomatic stage relates to scapolitization of limited parts of gabbroic rocks. An external saline fluid, which is composed of major NaCI and minor KCI and P205 components, impacted locally on Pasveh gabbros and formed the second metasomatic stage. Possible sources of Na and Cl are primary evaporites or brines, which were present in the host sediments of the gabbros. The carbonate-free nature of these hydrothermal fluids suggests that hydrothermal fluids responsible for the formation of scapolite in Pasveh gabbros are derived from marine evaporitic parentage.展开更多
It is demonstrated by the example of gem-quality ruby,spinel,beryl,scapolite,kunzite,danburite,and jeremejevite from various deposits that,under the conditions of staged mineral formation,their later low-temperature g...It is demonstrated by the example of gem-quality ruby,spinel,beryl,scapolite,kunzite,danburite,and jeremejevite from various deposits that,under the conditions of staged mineral formation,their later low-temperature generations are regenerated as a result of growth-dissolution and can acquire high gem-quality properties.These crystals formed under lower-temperature mineralization conditions.One of the characteristic features of such crystals,in addition to paragenetic associations,is their crystal morphology.The features of facet sculptures and internal structure,resulting from growth and dissolution,reflect their enhancement processes.These processes can occur both in parent rocks and in various types of cavities,such as pegmatite chambers,miaroles,or in crushed zones and fracture structures typically filled with later minerals,including loose aggregates and clay fractions.展开更多
基金the National Natural Science Foundation(11264040,No.11464045)The doctoral scientific research foundation of Xinjiang Normal University(XJNUBS1409)
文摘Natural scapolite including the S-2impurity is a typical silicate luminescent mineral.According to the formation conditions and chemical composition of natural scapolite,we synthesized Na_(4)Ca_(4)Al_(6)Si_(9)O_(24)(scapolite)by the high temperature solid-phase reaction,and prepared the synthetic scapolite phosphors activated with Ce^3+and Tb^3+.The photoluminescence(PL)properties of the obtained phosphors were studied.The results indicated that the PL intensity of green(545nm)emission corresponding to the 5 D4→7 F5 transition within Tb^3+in the Ce^3+,Tb^3+-codoped samples was much higher than that of the Tb^3+-doped samples.The PL properties of the samples activated with various Ce^3+concentrations were measured,and their fluorescence lifetime and energy transfer mechanism were analyzed.We proved that there was energy transfer from Ce^3+to Tb^3+,and the energy transfer efficiency was at its maximum when the Ce^3+to Tb^3+mass ratio was 0.02∶0.03.Upon measurement by chromaticity coordinates,we found that the luminescence of the samples could be adjusted in the green area with varying Ce^3+concentrations.We thus deem that scapolite phosphors Na4Ca4Al6Si9O24∶Ce^3+,Tb^3+are promising to become the new white LED phosphors.
文摘Pasveh gabbros are mafic component of a plutonic complex in the northwest Sanandaj- Sirjan Zone. These cumulative rocks are composed of plagioclase and calcic clinopyroxene （Cpx）, which yield unusually high CaO （〉19 wt.%） in whole-rock chemistry. Petrographical and geochemical data suggest that Pasveh gabbros can be divided into two groups： free scapolite and scapolite-bearing gabbros. The second group has higher Na20, K20, and P205 relative to free scapolite ones and is enriched in LIL （large ion lithophile） and HFS （high field strength） elements. Two stages of metasomatism affected the primary composition of mafic rocks. Firstly, high temperature reaction caused to invert primary high Ti clinopyroxene to low Ti cUnopyroxene＋high Ti amphibole. This reaction was extensive and included all gabbroic samples. Hydrothermal fluids involved in this process can be derived from dehydration reactions of country rocks or from other magmas incorporated in the formation of Pasveh complex pluton. The second metasomatic stage relates to scapolitization of limited parts of gabbroic rocks. An external saline fluid, which is composed of major NaCI and minor KCI and P205 components, impacted locally on Pasveh gabbros and formed the second metasomatic stage. Possible sources of Na and Cl are primary evaporites or brines, which were present in the host sediments of the gabbros. The carbonate-free nature of these hydrothermal fluids suggests that hydrothermal fluids responsible for the formation of scapolite in Pasveh gabbros are derived from marine evaporitic parentage.
文摘It is demonstrated by the example of gem-quality ruby,spinel,beryl,scapolite,kunzite,danburite,and jeremejevite from various deposits that,under the conditions of staged mineral formation,their later low-temperature generations are regenerated as a result of growth-dissolution and can acquire high gem-quality properties.These crystals formed under lower-temperature mineralization conditions.One of the characteristic features of such crystals,in addition to paragenetic associations,is their crystal morphology.The features of facet sculptures and internal structure,resulting from growth and dissolution,reflect their enhancement processes.These processes can occur both in parent rocks and in various types of cavities,such as pegmatite chambers,miaroles,or in crushed zones and fracture structures typically filled with later minerals,including loose aggregates and clay fractions.
