【作者】 王春芬；

【导师】 黄宁康；

【作者基本信息】 四川大学 ， 凝聚态物理， 2005， 硕士

【摘要】 七十年代以后,随着空间技术的发展,人们开始对α-Al₂O₃晶体辐照缺陷中的色心进行广泛的研究。在大量研究的各种色心中,了解最彻底的为α-Al₂O₃晶体中的F心和F⁺心;对α-Al₂O₃的离子注入掺杂研究中,主要是用各种金属单质离子,采用化合物离子尚未见报道。本论文工作就采用化合物离子CuCl⁺注入α-Al₂O₃,研究由此引起的色心行为,并对退火后的样品进行了SEM表面观察。主要工作和结果包括: 1.采用分子离子CuCl⁺离子注入α-Al₂O₃单晶,通过吸收谱以及荧光谱的测量,结果发现不同晶向的α-Al₂O₃晶体在不同注入条件下在高能端均有强烈的吸收。对吸收谱进行了高斯拟合以及荧光谱的分析确认,CuCl⁺离子注入α-Al₂O₃晶体产生的色心缺陷主要是阴离子色心,如F心、F⁺心、F₂心、F₂⁺心以及F₂⁺²心。 2.对注入后的试样在还原气氛下退火,对退火后的样品进行了光吸收谱及荧光谱的测量。结果发现与退火前相比,其吸收强度有不同程度的下降。证明了相应的色心数目因退火而减少了。我们还发现色心的减少很大程度取决于注入条件、晶向和退火温度。 3.对CuCl⁺离子注入α-Al₂O₃晶体退火后表面进行了SEM形貌观察。在样品表面所拍的照片中我们可以明显地观察到亚微米颗粒的存在,颗粒的大小也与注入条件,晶向和退火温度有关系。可以预计,合适的退火温度能在试样表面形成纳米颗粒。 4.通过对氧化物晶体退火色心消除情况的比较,发现离子注入在共价型氧化物晶体中产生的色心缺陷不易通过退火消除,而离子型的正相反。更多还原

【Abstract】 Since seventies of the 20^th century, people began to study irradiation damages in α-Al₂O₃ crystal due to the demands of development in space technology, many color centre in the damage of oxide crystals by ion implantation has been studied. Among them, F and F4 centre are most understood. Study in color centers of α-Al₂O₃ crystal by using ion implantation, usually, with different elemental metallic ions, however, study in them has not get been reported with compound ions. In our work, ion implantation in α-Al₂O₃ crystal was with a kind of molecular ions of compound CuCl⁺. The behaviors of color centers in α-Al₂O₃ crystal produced by CuCl⁺ ion implantation are reported in this paper, and surface morphologies of CuCl⁺ implanted α-Al₂O₃ after annealing with SEM observation were also reported in this paper.Several conclusions can be drawn as follows:1. Optical absorption and luminescence measurements have been done for the α-Al₂O₃ specimens implanted with CuCl⁺ ions. It is found that a strong absorption at UV section can be seen in optical absorption spectra for all of the specimens with different crystal orientations. The calculation of Gaussian fitting and measurements in luminescence confirm that there are several point defects such as F, F₂, F₂⁺, and F₂⁺2 centre in the CuCl⁺ -implanted α-Al₂O₃ samples.2. The; optical absorption intensities of the CuCl* implanted o-AlA ■ specimens are decreased by annealing treatment, this manifests that, thenumber of the color centers is decreased due to annealing. It is also found that decreases in number for different kinds of color centers are dependent greatly on implantation conditions, substrate orientation and annealing temperature.3. Sub-micrometer particles after annealing have been observed in the surface of the CuCl’ implanted a Ml)-, specimens by us-ing SEM technique. The size of particles is greatly dependent on implantation conditions, substrate orientation and annealing temperature. It is expected that particles with nano-meter size could be formed at the suitable annealing temperature.4. Comparing with the behaviors of el iminating color centre produced by ion impLantation in different oxide crystals through annealing. It seems more difficult to eliminate color centre in covalence oxide crystal than in ion oxide crystal.更多还原