Sr0.53Ba0.47Nb2O6 (SBN53) ceramics were reactively sintered from SrNb2O6 and BaNb2O6 powders. The formation temperature decreased from 1260°C for unseeded samples to 1130°C for the samples with 15.4 wt% seeds plus 0.85 mol% V2O5 at a heating rate of 4°C/min. For the V2O5-free samples, the activation energy was lowered from 554 ± 15 kJ/mol for unseeded samples to 241 ± 17 kJ/mol for the samples with 15.4 wt% seeds. In the V2O5-containing samples, densification and phase formation occurred simultaneously. In the V2O5-free samples, however, phase formation was completed before densification. In both cases, ceramics with 95% relative density were obtained. In all cases, SBN53 formed directly, rather than via a variety of intermediate SBN solid solutions. The microstructure evolution was also studied. 相似文献
The robust Bi7.53Co0.47O11.92 nanoflowers on the nickel foam are first designed by a simple solvent thermal reaction followed by calcining. For its unique structural stability and good electrical conductivity, the Bi7.53Co0.47O11.92 nanoflowers exhibit high specific capacitance of 1046 F g?1 at 1 A g?1 and outstanding rate capability (81.7% capacitance retention at 10 A g?1) along with good cycling stability (80.5% capacitance retention after 3000 cycles). The asymmetric supercapacitor assembled with Bi7.53Co0.47O11.92 and activated carbon delivers a high energy density of 41.1 Wh kg?1. This research provides a guiding strategy for the synthesis of high-performance supercapacitor electrode material based on the bismuth.
Graphical abstract
Robust Bi7.53Co0.47O11.92 nanoflowers were first designed by a feasible method and exhibited high specific capacitance and outstanding rate capability.
Studies are reported of the upper critical fields of Nb0.53Ti0.47-Ge multilayers consisting of thick Ge layers and varying-thickness Nb0.53Ti0.47 layers. Both the angular dependence and the temperature dependence of the upper critical fields indicate a dimensional crossover at a Nb0.53Ti0.47 layer thickness near 200 Å. All the 2D samples display a cusplike upper critical field angular dependence with a sharper cusp for thinner Nb0.53Ti0.47 layers. The parallel upper critical fields are tentatively fitted with an expression combining the 2D field dependence of Rickayzen, the paramagnetic limiting behavior of Maki, and the disorder-related Coulomb interaction effects of Maekawa and Fukuyama. The perpendicular fields are fitted with the Maekawa, Ebisawa, and Fukuyama theory; better agreement is obtained for thinner Nb0.53Ti0.47 sublayers when the paramagnetic limiting effect is included. 相似文献
The performance degradation of In0.53Ga0.47As p-i-n photodiodes, subjected to a 220-MeV carbon particle irradiation in the fluence range 1010 to 1013 cm–2, is reported. It is shown that the increase of the dark current scales roughly with the displacement damage created in the n-type InGaAs region. The degradation of the photo-current, on the other hand, does not scale with the displacement damage, for all irradiations studied. Therefore, it is believed that the photo-current suffers from increased surface recombination, which is related to the ionization damage created in the passivation layer. 相似文献
Measurements of the static current-voltage characteristics of photoexcited minority electrons in p-In0.53Ga0.47As are reported. Photoluminescence measurements are also presented. These results are discussed in terms of the theory for high field photoconductivity and the recently reported velocity-field characteristics for minority electrons in In0.53Ga0.47As. 相似文献