CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 4
·5770-5775
·
IF 5.532
Yan Hao,Yibo Zhang,Biao Liu,Kuibao Zhang
In this work, MgAl 2 O 4 : Cr 3+ transparent ceramics have been synthesized by the hot press sintering techniques, and the effect of the sintering aid Gd 2 O 3 and its content on the densification, microstructure, and optical, photoluminescence was studied and discussed. The relative density reached 99.29% with 0.8 wt% Gd 2 O 3 as a sintering aid, and the optical transmittance at 686 nm and 1446 nm were approximately 76%. As Gd 2 O 3 content continued to increase, the grain size of the ceramics became smaller and uniform, accompanied by some pores with the size of ～1 μm. The ceramics with 4.0 wt% Gd 2 O 3 showed a higher transmittance, of 82% at 1446 nm. Additionally, Gd 2 O 3 was helpful for Cr 3+ in the sites of octahedral symmetry, which increased the quantum yield. The quantum yield of MgAl 2 O 4 : Cr 3+ with 0.8 wt% Gd 2 O 3 was about 0.175, which was 36% higher than that of ceramic without Gd 2 O 3 . In short, the sintering aid Gd 2 O 3 not only contributed to improving the densification, homogenizing the grain size, and heightening the optical transmittance but also enhanced the quantum yield of Cr 3+ .
研究领域:
材料科学
·
陶瓷
·
光学材料
·
固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 7
·8450-8459
·
IF 2.478
Zhang Pengfei,Ma Weibing,Wang Shenghui,Guo Jingdong,Hong Jingnan,Ba Ruiqing,He Xinghui,Li Jing
Aurivillius-type piezoceramics, Na 0.15− x Li x Bi 2.85− x Ce x Ti 0.7 Nb 1.3 O 9 (NBTN-LC100 x ; x = 0, 0.02, 0.04, 0.06), were fabricated by the solid-state reaction method. The crystal structure, surface microstructure, and electrical properties of NBTN-LC100x ceramics were studied systematically. The XRD revealed that the (LiCe) co-doping induced lattice distortion and the orthogonality of ceramics were weakened. The grain size decreased obviously from 23.1 to 9.1 µm and the Curie temperature ( T C ) decreased from 877 to 853 °C as the increase of (LiCe) content. As x = 0.04, the NBTN-LC100 x (NBTN-LC4) ceramics had the best performance, its T C , tanδ at 500 °C, E C , and P r were 861 °C, 7.61%, 62 kV/cm, and 3.4 µC/cm 2 , respectively. The piezoelectric property was enhanced significantly and optimal d 33 value was about 20.7 pC/N at x = 0.04 for NBTN-LC100 x ceramics. In addition, the NBTN-LC4 ceramics possessed a good thermal stability after annealing at 850 °C for 2 h. The high d 33 , high T C , low tanδ, good thermal stability of NBTN-LC4 ceramics make it is potential candidate in high-temperature electronic devices.
研究领域:
材料科学
·
陶瓷
·
压电材料
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Shengquan Yu,Wei Jing,Mingjing Tang,Tao Xu,Wenlong Yin,Bin Kang
The highly transparent Nd:YAG ceramics were prepared by using powders synthesized by citrate sol-gel method. The citrate sol-gel method could avoid defects of the solid-phase reaction method and the liquid phase co-precipitation method in preparing Nd:YAG ceramic powders with the ratio of (Nd 3+ , Y 3+ ):Al 3+ equal to 3:5. The dried gel was the three dimensional net-shaped porous structure. When the dried gel was calcined at 500 °C in oxygen, pure YAG phase formed directly with no intermediate phases. The Nd:YAG powders calcined at 800 °C had maximum particle size near 500 nm. These powders were not equiaxed and there were dumbbell-like and annular grains. The highly compact Nd:YAG ceramics could be well sintered at 1750 °C for 12 h in vacuum atmosphere, and these sample had the average grain size about 3.8 μm. The polished Nd:YAG ceramics was highly transparent, and the transmittances at 1064 nm and 400 nm were 83.4% and 74.2%, respectively. The fluorescence emission spectrum implied high possibility of realizing laser output at 1064 nm by pumping at 808 nm. Generally, the citrate sol-gel method was also a reliable choice for preparing high quality Nd:YAG transparent ceramics.
研究领域:
材料科学
·
陶瓷
·
光学材料
·
激光技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Jingxian Yang,Xiaoyan Shu,Fen Luo,Lan Wang,Yucheng Gu,Jianjun Wu,Xirui Lu
The disposal of strontium (Sr) from nuclear reactions has been a great challenge in the nuclear industry. Based on four kinds of occupation methods, a series of SrO-doped Gd 2 Zr 2 O 7 compositions with the general formula Gd 2-2 x /3 Sr x Zr 2 O 7 , Gd 2 Zr 2- x /2 Sr x O 7 , Gd 2- x Sr x Zr 2 O 7- x /2 and Gd 2 Zr 2- x Sr x O 7- x (0.0 ≤ x ≤ 2.0) were prepared by a high temperature sintering method solid state route. The influences of Sr substitution on the structure modifications, solid nuclear mobility, microstructure, and element distribution were studied. Our results show that the four sets of samples reach the maximum solid solubility within the range of x > 2.0, 1.5 < x ≤ 2.0, 1.0 < x ≤ 1.5, 1.0 < x ≤ 1.5, respectively. It was found out that the compound phase of SrZrO 3 and pyrochlore appeared in all the samples. In addition, the amount of the SrZrO 3 increases while the amount of the pyrochlore decrease and that of Sr 2+ increases.
研究领域:
材料科学
·
核废料管理
·
陶瓷
·
固态化学
✓ 已验证
DOI
高影响因子
SCRIPTA MATERIALIA
·
2018
·
IF 4.163
Lili Guan,Jian Li,Xiwen Song,Jinxiao Bao,Tao Jiang
Flash sintering of Sm 2 O 3 doped CeO 2 ceramics can be triggered at 25 °C due to the presence of graphite. The current density rise non-linearly to a set limit value in the voltage control stage under an initial electric field of 30 V cm −1 . The calculated conductivity activation energy in this stage is 0.30 eV, which is closely in relation to the electronic conduction of graphite. As graphite is beginning to oxidize, the conductivity of the sample rapidly decreases. While graphite has been completely oxidized, the specimen temperature provides adequate support for the persistence of flash sintering process .
研究领域:
材料科学
·
陶瓷
·
固体离子学
·
电场辅助烧结
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）