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
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
基金Project supported by the National Natural Science Foundation of China and the Foundation of the Key Laboratory of Structural Chemistry of China.
文摘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.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10274026)
文摘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.