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用内转换电子穆斯堡尔谱(CEMS)和慢正电子束研究了含3%Y2O3的ZrO2中57Fe离子(100keV,3×1016at./cm2)注入态及其在氢气氛中退火的热力学行为.注入态以Fe3+,Fe2+和Fe0存在,它们分别是Fe3+-V(空位)复合体、二聚体和超顺磁颗粒.经400,500℃退火后,Fe3+-V分解,分别出现了α-Fe的前期相和α-Fe纳米颗粒.含Fe的ZrO2(Y)混合导电的出现可能是和Fe的不同价态及其相对含量有关
关键词: 相似文献
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Simulate anneal arithmetic has been used to settle the problem of time bunching on a pulsed slow-positron beam device. This paper has searched for the parameters of the device in a large scope and achieved the time resolution within 150ps at the target with accelerating voltage in a range of 0.5-30kV. 相似文献
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This paper studies the evolution of native point defects with
temperature in ZnO single crystals by positron lifetime and
coincidence Doppler broadening (CDB) spectroscopy, combined with the
calculated results of positron lifetime and electron momentum
distribution. The calculated and experimental results of the
positron lifetime in ZnO bulk ensure the presence of zinc
monovacancy, and zinc monovacancy concentration begins to decrease
above 600℃ annealing treatment. CDB is an effective method
to distinguish the elemental species, here we combine this technique
with calculated electron momentum distribution to determine the
oxygen vacancies, which do not trap positrons due to their positive
charge. The CDB spectra show that oxygen vacancies do not appear
until 600℃ annealing treatment, and increase with the increase
of annealing temperature. This study supports the idea that green
luminescence has a close relation with oxygen vacancies. 相似文献
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本文将慢正电子湮灭多普勒展宽谱技术,应用于对SiC表面热氧化生长的SiO2特性的研究.S参数和W参数在退火前后的变化,直观的反映出SiO2/SiC表面氧化层中空位型缺陷浓度的改变.通过与SiO2/Si样品的对比,证实C元素及其诱生空位型缺陷的存在,很可能是影响SiO2/SiC氧化层质量和SiC MOS击穿特性的重要因素,后退火工艺可以提高SiO2/SiC中氧化层的致密性.实验表明,慢正电子湮灭多普勒展宽谱是研究热氧化SiO2特性的有效手段 相似文献
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