贵州遵义二叠系锰矿床中稀土元素赋存状态研究

贵州遵义地区是中国华南二叠系锰矿重要富集区之一,锰资源储量逾2亿t。通过对遵义长征、南茶及统子窝锰矿床23件岩矿石样品稀土元素组成进行测试分析,发现锰矿床普遍富集稀土元素,其中矿石∑REE总量介于326.3~1138.9×10~(-6)之间,平均538.84×10~(-6)。锰矿中凝灰岩∑REE总量最高,达到1824.5×10~(-6)。电子探针和能谱分析结果表明,锰矿中稀土元素主要以稀土独立矿物的形式存在,其中独居石、磷钇矿是最主要的稀土矿物,其以富集Ce,La和Nd为主要特征,部分矿段重稀土元素Y相对富集,指示遵义二叠系锰矿床伴生稀土组分主要以富集轻稀土元素为主要特征。     

绝缘氧化层上自离子注入Si薄膜W线发光性能的调控

对SOI基片上的Si薄膜进行了一系列Si⁺自注入和热退火的改性实验,并利用低温光致发光(PL)光谱对这些Si薄膜样品的发光性能进行了测试. 在这些SOI样品的PL光谱中观察到了丰富的光学结构,包括D₁,D₂,D₃,X以及异常尖锐的W线. 通过对比在同等光谱测试条件下的W线归一化强度,获得了针对SOI基片发射W线较为理想的自注入和热退火参数. 同时,还对D系列发光峰以及W线的缺陷起源和光学性质进行了很好的讨论. 关键词： SOI结构 自离子注入 W线 近红外发光器件     

Study on the defect-related emissions in the light self-ion-implanted Si films by a silicon-on-insulator structure

This paper reports that the Si + self-ion-implantation are conducted on the silicon-on-insulator wafers with the 28 Si + doses of 7×10 12,1×10 13,4×10 13,and 3×10 14 cm 2,respectively.After the suitable annealing,these samples are characterized by using the photoluminescence technique at different recorded temperatures.Plentiful emission peaks are observed in these implanted silicon-on-insulator samples,including the unwonted intense P band which exhibits a great potential in the optoelectronic application.These results indicate that severe transformation of the interstitial clusters can be manipulated by the implanting dose at suitable annealing temperatures.The high critical temperatures for the photoluminescence intensity growth of the two signatures are well discussed based on the thermal ionization model of free exciton.     

扩散过程对自组织生长量子点密度影响的模拟研究

考虑六方格子衬底上的沉积粒子扩散过程,本文利用Monte Carlo方法对自组织生长岛的面密度进行了研究.模拟得到了岛的生长形貌图,结果表明生长的岛数与扩散步数成反比且存在最大23;岛覆盖率,由岛的覆盖率可估算量子点分布的最大面密度.     

Photoluminescence evolution in self-ion-implanted and annealed silicon

Si⁺ ion-implanted silicon wafers are annealed at different temperatures from room temperature to 950~℃ and then characterized by using the photoluminescence (PL) technique at different recorded temperatures (RETs). Plentiful optical features are observed and identified clearly in these PL curves. The PL spectra of these samples annealed in different temperature ranges are correspondingly dominated by different emission peaks. Several characteristic features, such as an R line, S bands, a W line, the phonon-assistant W^\rm TA and Si^\rm TO peaks, can be detected in the PL spectra of samples annealed at different temperatures. For the samples annealed at 800~\du, emission peaks from the dislocations bounded at the deep energy levels of the forbidden band, such as D_1 and D₂ bands, can be observed at a temperature as high as 280~K. These data strongly indicate that a severe transformation of defect structures could be manipulated by the annealing and recorded temperatures. The deactivation energies of the main optical features are extracted from the PL data at different temperatures.     

毕节地区晚二叠世煤层稀土元素的示踪研究

对取自贵州西部毕节地区,晚二叠世11个可采煤层的13个样品的稀土元素进行了电感耦合等离子体质谱法分析。研究发现：海洋来源对稀土元素的富集作用极其微弱;来自植物成因的物质来源小于1%;稀土元素的物质来源主要受陆源影响和控制。煤层与玄武岩稀土元素的∑REE,LREE,HREE,以及稀土元素配分模式有相似性。∑REE值最高的M12煤层形成于龙潭晚期,而这一时期玄武岩喷发集中于包括毕节地区的贵州西部。认为毕节晚二叠世煤层的稀土元素属于陆源成因沉积,峨眉山玄武岩是煤层稀土元素的主要物质来源和控制因素。     

贵州织金三甲寒武系戈仲伍组含磷岩系稀土富集规律研究

对贵州织金三甲地区寒武系底部戈仲伍组含磷岩系稀土元素、微量元素和一些常量元素等在剖面上的变化规律进行系统的研究，并结合剖面上小壳动物化石富集特点，认为寒武系底部戈仲伍组中有两个磷和稀土成矿期，稀土含量与磷含量成显著的正相关关系，而与小壳动物化石丰度没有显著相关性。