Yuying HAO
,
Bingshe XU
,
Zhixiang GAO
,
Hua WANG
,
Hefeng ZHOU
,
Xuguang LIU
材料科学技术（英）
A new electroluminescent material, salicylaldehyde anil zinc (SAZ) was synthesized, which can form high quality, thermal stability, nano-scale amorphous films by vacuum evaporation. Its structure, thermal stability were characterized by infrared (IR) spectra, differential thermal analysis-thermogravimetry (DTA-TG) analysis, respectively. The optical properties of SAZ were investigated by UV absorption spectra, Photoluminescence (PL) excitation and emission spectra. The highest occupied molecular orbits (HOMO), lowest unoccupied molecular orbits (LUMO) and optical band gap were evaluated by cyclic voltammetry curve and optical absorption band edge. The electroluminescent devices using SAZ as the emissive layer emit green light with a peak wavelength at 509 nm and a brightness of about 3.1 cd/m2.
关键词:
Salicylaldehyde anil zinc
,
光学性质
,
电子能级结构
Shengyu JIANG
,
Jiancheng ZHANG
,
Feng GU
,
Yue SHEN
,
Hua WANG
材料科学技术（英）
Glass-ceramics containing β-quartz as a main crystal phase based on the system of SiO2-Al2O3-Li2O-K2O-MgO-ZnO were investigated for the application to magnetic storage substrate for higher storage capacity. Parent glasses were prepared, then nucleated and crystallized at certain temperatures for 3~4 h. The crystallization kinetics of glass-ceramics was also studied. The grain size was estimated by Scherrer formula and image treatment of transmission electron microscopy (TEM). The results π showed that the Avrami exponent was determined to be 3.88, the activation energy 189±7 kJ/mol and the grain size 30~60 nm. A detailed microstructure of the glass-ceramics, including grain distribution and the morphology of nano-crystalline was characterized by TEM, X-ray diffraction (XRD), differential scanning calorimeter (DSC), differential thermal analysis (DTA). The relationship between microstructure and mechanical properties was also discussed.
关键词:
Glass-ceramics
,
动力学
,
磁盘基片
Wenhui MA
,
Gang XIE
,
Hua WANG
材料科学技术（英）
The thermal expansion behavior of La1-xSrxMn1-yCoyO3-d (x=0.2~0.4, y=0.1~0.3) perovskites in air has been investigated. The average linear thermal expansion coefficients increased with increasing Sr content up to 40 mole fraction or Co content up to 30 mole fraction. The expansion is generally attributed to an increase in the average cation radius as some of the cations in the perovskite are reduced in valence when oxygen ions are removed from the structure.
关键词:
Thermal expansion
,
null
,
null
