排序方式: 共有12条查询结果,搜索用时 31 毫秒
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对用离子束溅射制备的Ni0.8Co0.2-SiO2颗粒膜的Hall效应进行了研究.当Ni0.8Co0.2合金的含量为43vol%时,在9.5×105A/m的外磁场下,样品的室温Hall电阻率达6.3μΩ·cm ,高于普通磁性金属两个数量级以上,还研究了不同NiCo组分样品的电阻率与温度的关系(95—300K),发现x<xc(逾渗组分)时,电阻率与-logT成正比,电阻温度系数为负;当x<xc时,逐渐呈现金属性;而当x≈xc时,为过渡态.还用透射电子显微镜和振动样品磁强计等手段对样品的微结构和磁性进行了对比研究,表明金属-绝缘体颗粒膜中在逾渗阈值附近有较大的Hall效应,这与样品的微结构有密切关系.
关键词: 相似文献
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The intensity-dependent two-photon absorption and nonlinear refraction coefficients of GaP optical crystal at 800 nm were measured with time-resolved femtosecond pump-probe technique. A nonlinear refraction coefficient of 1.7×10-17 m2/W and a two-photon absorption coefficient of 1.5×10-12 m/W of GaP crystal were obtained at a pump intensity of 3.5×1012 W/m2. The nonlinear refraction coefficient saturates at 3.5×1012 W/m2, while the two-photon absorption coefficient keeps linear increase at 6×1012 W/m2. Furthermore, fifth-order nonlinear refraction of the GaP optical crystal was revealed to occur above pump intensity of 3.5×1012 W/m2. 相似文献
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在室温和低温下,测试了有序Ga0.52In0.48P的时间分辨光致发光谱.对实验结果的分析表明,有序GaInP的发光呈双指数规律衰退.室温下,快过程的时间常数在128~250ps范围,低温77K下则都有所变慢,大约在186~564ps范围内;慢过程的时间常数根据不同样品有很大差异,室温下大约在308~1832ps之间变化,低温77K下,则在纳秒量级,最长的甚至达到28ns以上.对两个过程的时间常数随激发功率密度变化的研究表明,快过程对应于有序区域中载流子的复合,慢过程则对应于有序区域和无序区域的空间分离中
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时间分辨光致发光谱
III-V族半导体
有序合金 相似文献
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The spectral resolved femtosecond pump-probe experiment is applied to measure the third order nonlinear refractive index coefficient, two-photon absorption coefficient of GaP crystal, and the chirp parameter of the input laser pulses. The results show that nonlinear refractive index coefficient is 2× 10-18 m2/W, twophoton absorption coefficient is 2× 10-11 m/W at wavelength of 783.5 nm, and the chirp parameter of laser pulse is l× 1025 s-2. Furthermore, the mechanism of nonlinear refraction due to two-photon absorption in GaP crystal and experimental results are discussed. 相似文献
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The spectral resolved femtosecond pump-probe experiment is applied to measure the third order nonlinear refractive index coefficient, two-photon absorption coefficient of GaP crystal, and the chirp parameter of the input laser pulses. The results show that nonlinear refractive index coefficient is 2 × 10 -18 m2/W, two-photon absorption coefficient is 2×10-11 m/W at wavelength of 783.5 nm, and the chirp parameter of laser pulse is 1×1025 s-2. Furthermore, the mechanism of nonlinear refraction due to two-photon absorption in GaP crystal and experimental results are discussed. 相似文献
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