The effects of Sn addition on core loss and texture of non-oriented electrical steels were investigated. Experiments revealed that the core loss of non-oriented electrical steels could be obviously decreased and the i...The effects of Sn addition on core loss and texture of non-oriented electrical steels were investigated. Experiments revealed that the core loss of non-oriented electrical steels could be obviously decreased and the intensity of {111 } texture and { 112} texture of final annealed specimens could be markedly reduced by Sn addition. The reasons for reducing core loss and the intensity of unfavorable texture were analyzed.展开更多
Development of advanced display and lighting technology such as field emission displays and plasma display panels requires phosphor which has a high efficiency and low degradation. Particle sizes and the locations of ...Development of advanced display and lighting technology such as field emission displays and plasma display panels requires phosphor which has a high efficiency and low degradation. Particle sizes and the locations of dopants in the hosts take an important role in the luminescence emissions of phosphors. ZnO nanoparticles are widely employed in plasma field emission display devices and well investigated;however, lanthanide (Ln3+) doped ZnO needs more investigations. In ZnO:Eu the lanthanide ions (Eu3+) may occupy either Zn2+ lattice site or on surface of ZnO crystal. The emissions of Eu3+ ion on the surface are the characteristic of Eu2 O3 , which leads to weak luminescence emission. To observe such phenomena, nanoparticles of ZnO, 2 at.% Eu3+ doped ZnO (ZnO:Eu) and ZnO:Eu covered with yattria matrix were prepared by wet chemical method at low temperature. The prepared nanoparticles were characterized by XRD and TEM. XRD data reveal the significant phase segregation of the annealed nanoparticles compared with lower heated samples. This phase segregation of Eu3+ ion establishes responsible for the decrease luminescence intensity of annealed ZnO:Eu nanoparticles compared with the as-prepared ZnO:Eu nanoparticles. Improvement on luminescence emissions could be achieved only for the as-prepared ZnO:Eu nanoparticles while covered with yattria matrix.展开更多
The fundamental characteristics of varied initial core-sizes of Ba Ti O3（BT） and its influential role on the morphology and dielectric properties of Ba Ti O3@0.6 Ba Ti O3-0.4 Bi Al O3（BT@0.6 BT-0.4 BA） ceramic sam...The fundamental characteristics of varied initial core-sizes of Ba Ti O3（BT） and its influential role on the morphology and dielectric properties of Ba Ti O3@0.6 Ba Ti O3-0.4 Bi Al O3（BT@0.6 BT-0.4 BA） ceramic samples were studied. Alkoxide sol-precipitation method was adopted as revised chemical route to synthesize the constituent ＂core＂ BT powders in a dispersed phase, whereas the distinctive initial nano-sized particles were affected by the pre-calcination temperatures（600-900 ℃）.The microstructure of the uncoated BT ceramics revealed an exaggerated grain growth with an optimized dielectric constant（ε（max） 〉9 000） whilst the coated ceramics behaved otherwise（grain growth inhibited） when sintered at an elevated temperature. Regardless of the previously studied solubility limit（about 0.1%） of BT-BA samples, BT@0.6 BT-0.4 BA maintained a maximum dielectric constant（ε（max）） ranging from 1 592 to 1 708 and tan δ less than 2% under a unit mole ratio at room temperature. In view of all these analyses, the initial nanometer sizes of the as-prepared BT-core powders combined with the increase effect of cation substitutions of Bi^（3＋） and Al^（3＋） in the shell content, induced the diffuse transition phase of BT@0.6 BT-0.4 BA composition.展开更多
文摘The effects of Sn addition on core loss and texture of non-oriented electrical steels were investigated. Experiments revealed that the core loss of non-oriented electrical steels could be obviously decreased and the intensity of {111 } texture and { 112} texture of final annealed specimens could be markedly reduced by Sn addition. The reasons for reducing core loss and the intensity of unfavorable texture were analyzed.
文摘Development of advanced display and lighting technology such as field emission displays and plasma display panels requires phosphor which has a high efficiency and low degradation. Particle sizes and the locations of dopants in the hosts take an important role in the luminescence emissions of phosphors. ZnO nanoparticles are widely employed in plasma field emission display devices and well investigated;however, lanthanide (Ln3+) doped ZnO needs more investigations. In ZnO:Eu the lanthanide ions (Eu3+) may occupy either Zn2+ lattice site or on surface of ZnO crystal. The emissions of Eu3+ ion on the surface are the characteristic of Eu2 O3 , which leads to weak luminescence emission. To observe such phenomena, nanoparticles of ZnO, 2 at.% Eu3+ doped ZnO (ZnO:Eu) and ZnO:Eu covered with yattria matrix were prepared by wet chemical method at low temperature. The prepared nanoparticles were characterized by XRD and TEM. XRD data reveal the significant phase segregation of the annealed nanoparticles compared with lower heated samples. This phase segregation of Eu3+ ion establishes responsible for the decrease luminescence intensity of annealed ZnO:Eu nanoparticles compared with the as-prepared ZnO:Eu nanoparticles. Improvement on luminescence emissions could be achieved only for the as-prepared ZnO:Eu nanoparticles while covered with yattria matrix.
基金Funded by NSFC-Guangdong Joint Funds of the Natural Science Foundation of China(No.U1601209)the National Key Basic Research Program of China(973 Program)(No.2015CB654601)National Natural Science Foundation of China(No.51372191)
文摘The fundamental characteristics of varied initial core-sizes of Ba Ti O3（BT） and its influential role on the morphology and dielectric properties of Ba Ti O3@0.6 Ba Ti O3-0.4 Bi Al O3（BT@0.6 BT-0.4 BA） ceramic samples were studied. Alkoxide sol-precipitation method was adopted as revised chemical route to synthesize the constituent ＂core＂ BT powders in a dispersed phase, whereas the distinctive initial nano-sized particles were affected by the pre-calcination temperatures（600-900 ℃）.The microstructure of the uncoated BT ceramics revealed an exaggerated grain growth with an optimized dielectric constant（ε（max） 〉9 000） whilst the coated ceramics behaved otherwise（grain growth inhibited） when sintered at an elevated temperature. Regardless of the previously studied solubility limit（about 0.1%） of BT-BA samples, BT@0.6 BT-0.4 BA maintained a maximum dielectric constant（ε（max）） ranging from 1 592 to 1 708 and tan δ less than 2% under a unit mole ratio at room temperature. In view of all these analyses, the initial nanometer sizes of the as-prepared BT-core powders combined with the increase effect of cation substitutions of Bi^（3＋） and Al^（3＋） in the shell content, induced the diffuse transition phase of BT@0.6 BT-0.4 BA composition.
