期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Theoretical studies on the band structures of superconducting solid compounds: Nb3X (X=Si, Ge, Sn, Pb)
1
作者 CAI, Shu-Hui LI, Jun LIU, Chun-WanFujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, State Key Laboratory of Structural Chemistry, Fuzhou, Fujian 350002, China 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1994年第5期385-391,共7页
The band structures of several analogous superconducting A-15 type solid compounds, Nb3X (X=Si, Ge, Sn, Pb), have been calculated by use of the tight-binding method within the Extended Huckel approximation (EHT). By a... The band structures of several analogous superconducting A-15 type solid compounds, Nb3X (X=Si, Ge, Sn, Pb), have been calculated by use of the tight-binding method within the Extended Huckel approximation (EHT). By analysis of their energy bands, densities of states and crystal orbital overlap populations, the dependence of the superconducting transition temperatures (Tc) on the electronic structures and bondings is qualitatively elucidated. 展开更多
关键词 nb3x EHT band structures Tc.
原文传递
Ca[(Li_(1/3)Nb_(2/3))_(1-x)Ti_(3x)]O_(3-δ)陶瓷微波介电性能研究
2
作者 边小兵 刘运 刘鹏 《陕西师范大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第2期31-33,共3页
研究了添加B2O3的Ca[(Li1/3Nb2/3)1-xTi3x]O3-δ(0≤x≤0.2)(CLNT)陶瓷的微波介电性能.在整个组分范围内检测到单一的正交相.随着x从0增加到0.2,介电常数(k)将从30增至89,Qf值则下降到3820GHz,谐振频率温度系数(TCF)从-16×10-6/℃... 研究了添加B2O3的Ca[(Li1/3Nb2/3)1-xTi3x]O3-δ(0≤x≤0.2)(CLNT)陶瓷的微波介电性能.在整个组分范围内检测到单一的正交相.随着x从0增加到0.2,介电常数(k)将从30增至89,Qf值则下降到3820GHz,谐振频率温度系数(TCF)从-16×10-6/℃增加到22.4×10-6/℃.当B2O3添加1.0%时,CLNT陶瓷的烧结温度可以从1150℃降至970℃而不降低微波介电性能.940℃烧结后,x=0.1试样的微波性能为k=50,Qf=6500GHz,温度系数为-7.6×10-6/℃. 展开更多
关键词 Ca[(Li1/3Nb2/3)1-xTi3x]O3-δ 微波介电性能 低温共烧陶瓷 氧化硼
下载PDF
The transverse laser induced thermoelectric voltages in step flow growth (1-x)Pb(Mg_(1/3)Nb_(2/3))O_(3-x)PbTiO_3 thin films
3
作者 尚杰 张辉 +2 位作者 李勇 曹明刚 张鹏翔 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第10期452-457,共6页
This paper reports that the transverse laser induced thermoelectric voltages (LITV) axe observed for the first time in the step flow growth (1- x)PD(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT, x = 0.20, 0.33, 0.50) thin fi... This paper reports that the transverse laser induced thermoelectric voltages (LITV) axe observed for the first time in the step flow growth (1- x)PD(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT, x = 0.20, 0.33, 0.50) thin films deposited on vicinal-cut strontium titanate single crystal substrates. Because lead magnesium niobate-lead titanate is a solid solution of lead magnesium niobate (PMN) and lead titanate (PT), there are two types of signals. One is wide with a time response of a microsecond, and the other superimposed with the wide signal is narrow with a time response of a nanosecond. The transverse LITV signals depend on the ratio of PMN to PT drastically. Under the irradiation of 28-ns pulsed KrF excimer laser with the 248-nm wavelength, the largest induced voltage is observed in the 0.50Pb(Mg1/3Nb2/3)O3-0.50 PbTiO3 films. Moreover, the effects of film thickness, substrates, and tilt angles of substrates are also investigated. 展开更多
关键词 laser induced thermoelectric voltage (1- x)PD(Mg1/3Nb2/3)O3-xPbTiO3 films anisotropic Seebeck effect
下载PDF
Fe_(73.5)Si_(13.5-x)Ge_xB_9Cu_1Nb_3(x=3,6)非晶合金的结晶动力学 被引量:1
4
作者 汪汝武 刘静 +2 位作者 甘章华 曾春 张凤泉 《材料研究学报》 EI CAS CSCD 北大核心 2014年第3期204-210,共7页
用标准单辊甩带技术在大气环境下制备Fe73.5Si13.5-x Gex B9Cu1Nb3(x=3,6)非晶条带,分别在470℃、510℃、550℃和590℃对非晶条带进行真空等温退火1 h后,在非晶基体中形成了纳米晶相。用X射线衍射(XRD),透射电镜(TEM)和差示扫描量热法(D... 用标准单辊甩带技术在大气环境下制备Fe73.5Si13.5-x Gex B9Cu1Nb3(x=3,6)非晶条带,分别在470℃、510℃、550℃和590℃对非晶条带进行真空等温退火1 h后,在非晶基体中形成了纳米晶相。用X射线衍射(XRD),透射电镜(TEM)和差示扫描量热法(DSC)测量研究了快淬态和热处理后样品的结构和结晶动力学。基于差热分析的数据,使用Kissinger,Ozawa和AugisBennett模型计算了非晶条带的结晶激活能,利用Johnson-Mehl-Avrami(JMA)方程计算了非晶条带初始结晶的局域Avrami因子n。局域Avrami因子n随晶化体积分数α的显著变化说明,非晶条带非等温初始结晶的机理在不同的晶化阶段是不同的。晶化初期的机理是扩散控制的三维形核和晶粒生长的整体晶化,形核速率逐渐减小;晶化中后期为一维形核和生长的表面晶化过程,形核速率近似为零。基于XRD和TEM测量结果,分别在510℃、550℃和590℃真空等温退火1 h后,在Fe73.5Si13.5-x Gex B9Cu1Nb3(x=3,6)非晶条带中析出的α-Fe(Si,Ge)相的平均晶粒尺寸D小于15 nm。 展开更多
关键词 材料科学基础学科 FE73 5Si13 5-xGexB9Cu1Nb3(x=3 6)结构 结晶动力学
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部