摘要
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.
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
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）.
