Upconversion （UC） and electrical properties of Na0.5Bi8.5-xErxTi7O27 （NBT-BIT-xEr, 0.00≤x≤0.25） ceramics were studied. Structural analysis revealed that a single inter-growth structured phase exists in all sampl...Upconversion （UC） and electrical properties of Na0.5Bi8.5-xErxTi7O27 （NBT-BIT-xEr, 0.00≤x≤0.25） ceramics were studied. Structural analysis revealed that a single inter-growth structured phase exists in all samples and the Er3＋ ion substituting for Bi3＋ at the A-site increases the orthorhombic distortion. Under the 980 nm laser excitation, two characteristic green emission bands and one red emission band were situated at 527, 548 and 670 nm, corresponding to the transitions 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2, respectively. The optimal photoluminescence （PL） were found in the NBT-BIT-0.20Er sample, and the emission color transforms from green to yellowish green. Temperature dependence of fluorescence intensity ratio （FIR） for NBT-BIT-0.20Er was measured ranging from 290 to 440 K and its maximum sensitivity was calculated to be about 0.0020 K-1 at 290 K. Dielectric measurements indicated that Tc slightly increased simultaneously with the decrease of tanS. Therefore, this ceramic has potential applications for high-temperature multifunctional devices.展开更多
Er^3+-doped SrBi4Ti4O15-Bi4Ti3O12(SBT-BIT-xEr^3+,x=0.00,0.05,0.10,0.15 and 0.20)inter-growth ceramics were synthesized by the solid-state reaction method.Structural,electrical and up-conversion properties of SBT-BIT-x...Er^3+-doped SrBi4Ti4O15-Bi4Ti3O12(SBT-BIT-xEr^3+,x=0.00,0.05,0.10,0.15 and 0.20)inter-growth ceramics were synthesized by the solid-state reaction method.Structural,electrical and up-conversion properties of SBT-BIT-xEr^3+ were investigated.All samples showed a single phase of the orthorhombic structure.Raman spectroscopy indicated that the Er^3+ substitution for Bi^3+ at A sites of the pseudo-perovskite layer increases the lattice distortion of SBT-BIT-xEr^3+ ceramics.The substitution of Bi^3+ by Er^3+ leads to a decrease of dielectric loss tanδ and an increase of conductivity activation energy.Piezoelectric constant d33 was slightly improved,but dielectric constant was decreased with the Er^3+ doping.The SBT-BIT-xEr^3+ ceramic with x=0.15 exhibits the optimized electrical behavior(d33~17 pC/N,tanδ~0.83%).Moreover,two bright green(532 and 548 nm)and one red(670 nm)emission bands were observed under the 980 nm excitation.Optimized emission intensity was also obtained when x=0.15 for the SBT-BIT-xEr^3+ ceramic.Therefore,this kind of ceramics ought to be promising candidates for multifunctional optoelectronic applications.展开更多
Two year’s research on the relationship between vegetable planting and S.officinarum growth indicates that vegetable inter-cropping has no negative effect on the yielding of S.officinarum.The competition for water,so...Two year’s research on the relationship between vegetable planting and S.officinarum growth indicates that vegetable inter-cropping has no negative effect on the yielding of S.officinarum.The competition for water,soil nutrition and sunshine between S.officinarum and vegetable are avoided due to carefully designed productive plan.It also indicates that while vegetable inter-cropping has influence,to certain extent,on soil temperature and soil water of the S.officinarum planting plot,it does not affect the growth of S.officinarum.The number,height and weight of S.officinarum stem remain in the normal range,while the land productivity is enhanced by this inter-cropping.It shows that the output of vegetable inter-cropping doubled (167.7～217.4 percent higher for cayenne,124～179.7 percent higher for frijole) than contrast.展开更多
基金This work was financially supported by the National Natural Science Foundation of China （Grant Nos. 51562014, 51262009 and 51602135）, the Natural Science Foundation of Jiangxi, China （Grant Nos. 20133ACB20002 and 20142BAB216009）, the Foundation Provincial Department of Education （GJJ150931 and GJJ 150911 ） and the Innovation Training Program of Jingdezhen Ceramic Institute （Grant No. 212050-008）, and partially sponsored by the Foundation of Training Academic and Technical Leaders for Main Majors of Jiangxi （Grant No. 2010DD00800）.
文摘Upconversion （UC） and electrical properties of Na0.5Bi8.5-xErxTi7O27 （NBT-BIT-xEr, 0.00≤x≤0.25） ceramics were studied. Structural analysis revealed that a single inter-growth structured phase exists in all samples and the Er3＋ ion substituting for Bi3＋ at the A-site increases the orthorhombic distortion. Under the 980 nm laser excitation, two characteristic green emission bands and one red emission band were situated at 527, 548 and 670 nm, corresponding to the transitions 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2, respectively. The optimal photoluminescence （PL） were found in the NBT-BIT-0.20Er sample, and the emission color transforms from green to yellowish green. Temperature dependence of fluorescence intensity ratio （FIR） for NBT-BIT-0.20Er was measured ranging from 290 to 440 K and its maximum sensitivity was calculated to be about 0.0020 K-1 at 290 K. Dielectric measurements indicated that Tc slightly increased simultaneously with the decrease of tanS. Therefore, this ceramic has potential applications for high-temperature multifunctional devices.
基金the National Natural Science Foundation of China(Grant Nos.51562014,51602135,51862016,51762024 and 61671224)the Natural Science Foundation of Jiangxi Province(20171BAB216012)the Foundation of Jiangxi Provincial Education Department(GJJ170789,GJJ170794 and GJJ170804).
文摘Er^3+-doped SrBi4Ti4O15-Bi4Ti3O12(SBT-BIT-xEr^3+,x=0.00,0.05,0.10,0.15 and 0.20)inter-growth ceramics were synthesized by the solid-state reaction method.Structural,electrical and up-conversion properties of SBT-BIT-xEr^3+ were investigated.All samples showed a single phase of the orthorhombic structure.Raman spectroscopy indicated that the Er^3+ substitution for Bi^3+ at A sites of the pseudo-perovskite layer increases the lattice distortion of SBT-BIT-xEr^3+ ceramics.The substitution of Bi^3+ by Er^3+ leads to a decrease of dielectric loss tanδ and an increase of conductivity activation energy.Piezoelectric constant d33 was slightly improved,but dielectric constant was decreased with the Er^3+ doping.The SBT-BIT-xEr^3+ ceramic with x=0.15 exhibits the optimized electrical behavior(d33~17 pC/N,tanδ~0.83%).Moreover,two bright green(532 and 548 nm)and one red(670 nm)emission bands were observed under the 980 nm excitation.Optimized emission intensity was also obtained when x=0.15 for the SBT-BIT-xEr^3+ ceramic.Therefore,this kind of ceramics ought to be promising candidates for multifunctional optoelectronic applications.
文摘Two year’s research on the relationship between vegetable planting and S.officinarum growth indicates that vegetable inter-cropping has no negative effect on the yielding of S.officinarum.The competition for water,soil nutrition and sunshine between S.officinarum and vegetable are avoided due to carefully designed productive plan.It also indicates that while vegetable inter-cropping has influence,to certain extent,on soil temperature and soil water of the S.officinarum planting plot,it does not affect the growth of S.officinarum.The number,height and weight of S.officinarum stem remain in the normal range,while the land productivity is enhanced by this inter-cropping.It shows that the output of vegetable inter-cropping doubled (167.7～217.4 percent higher for cayenne,124～179.7 percent higher for frijole) than contrast.
