新金刚石稳定性及晶体结构模型的研究  

Studies on Stability and Crystal Structure Model of New-diamond from Catalyzed Carbon Black

作　　者：温斌[1] 魏娜然[1] 马红军[1] 赵纪军[2] 李廷举[3] 

机构地区：[1]大连理工大学材料科学与工程学院,大连116023 [2]大连理工大学三束材料改性国家重点实验室,大连116023 [3]大连理工大学原材料特种制备实验室,大连116023

出　　处：《高等学校化学学报》2006年第7期1332-1335,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:50402025;50234020)资助

摘　　要：利用碳黑催化法制备了新金刚石粉末,并通过粉末X射线衍射(XRD)对不同时效处理后的新金刚石样品进行表征.结果表明,新金刚石是一种亚稳态的相,在室温下,随着放置时间的推移其晶体结构发生变化.根据XRD分析和模拟的XRD图谱,提出了用具有分数占位的“缺陷金刚石”模型来解释新金刚石结构随时间的变化规律.在该模型中,原子的占位数χ为0时,为面心立方结构(FCC),χ为1时,为金刚石结构.密度泛函理论计算结果表明,随χ的增加,其结构的稳定性也增加.可见,新金刚石是由FCC碳向金刚石结构过渡的中间态结构.After the synthesis of new-diamond by using a method of catalyzed carbon black, the crystal structure of the new-diamond after various aging-treatment time was investigated by X-ray diffraction （XRD）. The XRD patterns indicate that the new-diamond was a metastable phase, and the crystal structure of the new-diamond changed with the variation of the aging-treatment time at room temperature. Based on the XRD analysis and simulated XRD pattern, a ＂defective diamond＂ model with a fractional occupation site was proposed to explain the time-dependent the variation of the new-diamond crystal structure. In this model, the zero occupancy corresponds to a face-central cubic （FCC） crystal, while full occupation leads to a perfect diamond. A density functional theory computation further confirms the trend of increasing the stability during the evolution from FCC to diamond structure within our model. Therefore, we suggest that n-diamond is indeed an intermediate state between the FCC structure and diamond structure.

关 键 词：新金刚石 XRD 密度泛函理论 

分 类 号：O641[理学—物理化学]