低温区CsI掺杂的12CaO·7Al_2O_3型发射材料负离子的发射特性(英文)  

Low Temperature Anions Emission from CsI-Doped 12CaO·7Al_2O_3

作　　者：宁坤[1] 袁丽霞[1] 沈静[1] 李兴龙[1] 李全新[1] 

机构地区：[1]中国科学技术大学化学物理系,生物质洁净能源实验室,合肥230026

出　　处：《无机化学学报》2011年第5期963-970,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.50772107);国家“863”(No.2009AA05Z435);国家“973”(No.2007CB210206)资助项目

摘　　要：本文利用潮湿浸渍法将碘化铯(CsI)掺杂至12CaO·7Al2O3(C12A7)型负离子存储发射材料的表面并对其的结构与存储特性进行了X射线衍射和电子顺磁共振的表征,与此同时还对该材料的发射特性、离子发射分支比以及温度对发射强度的影响等方面进行了研究和分析。将实验和表征结果与未掺杂的C12A7进行对比后发现,C12A7表面上CsI的掺入很大程度上改善了该材料的发射特性。掺杂CsI后,在800 V·cm-1的引出场下,发射温度由570℃降低至470℃,与此同时,在同样的发射条件下,其发射强度也明显增强。低温区(<500℃)氧负离子O-的发射纯度接近100%。以上结果表明掺杂CsI至C12A7表面是一种在低温下获得氧负离子O-源的有效途径。A new method to generate low-temperature atomic oxygen anions（O-） emission by using the cesium iodide-doped 12CaO·7Al2O3（CsI-doped C12A7） has been provided by the present study.The maximal emission intensity of O-from the CsI-doped C12A7 at 650 ℃ reached about 1.38 μA·cm-2,which was much stronger than that from the un-doped C12A7 even at 750 ℃（0.78 μA·cm-2）.The initiative temperature of the O-emission from the CsI-doped C12A7 was about 470 ℃,which was also much lower than the initiative temperature from the un-doped C12A7（570 ℃）.High pure O-emission close to 100% could be obtained from the CsI-doped C12A7 under the lower temperature（500 ℃）.The emission features of the CsI-doped C12A7,including the emission distribution,temperature effect,and emission stability have been investigated in detail and compared with the un-doped C12A7.The structure and storage characteristics of the resulting material were also investigated via X-ray diffraction（XRD） and electron paramagnetic resonance（EPR）.

关 键 词：氧负离子 掺杂CsI的C12A7 发射分支比 存储特性 发射特性 

分 类 号：O647[理学—物理化学] O614.115[理学—化学]