CAJ | 학술논문

【目的】揭示空位晶体相场模型（VPFC）中二维周期性晶体相空位缺陷结构形貌。【方法】对标准晶体相场模型的自由能函数进行修正得到空位晶体相场模型，再利用空位晶体相场方程，研究二维相图中不同相晶体结构形貌图，以及晶体结构中出现空位的条件。【结果】当平均原子密度数值位于不同晶体相时，呈现出不同的二维周期性晶体结构形貌图。【结论】将晶体结构形貌图与其原子密度曲线对照，可见该模型中晶体相结构主要有六角“凸起”相、条状相和六角“凹坑”相。当平均原子密度数值位于相图中局部粒子相和六角“凸起”相之间时，二维周期性晶体结构中将出现空位，并且晶粒内部空位随机分布，空位数目与原子密度值有关。
【목적】게시공위정체상장모형（VPFC）중이유주기성정체상공위결함결구형모。【방법】대표준정체상장모형적자유능함수진행수정득도공위정체상장모형，재이용공위정체상장방정，연구이유상도중불동상정체결구형모도，이급정체결구중출현공위적조건。【결과】당평균원자밀도수치위우불동정체상시，정현출불동적이유주기성정체결구형모도。【결론】장정체결구형모도여기원자밀도곡선대조，가견해모형중정체상결구주요유륙각“철기”상、조상상화륙각“요갱”상。당평균원자밀도수치위우상도중국부입자상화륙각“철기”상지간시，이유주기성정체결구중장출현공위，병차정립내부공위수궤분포，공위수목여원자밀도치유관。
[Objective]The vacancy morphology of two-dimensional periodic crystal structure was estimated through the vacancy phase field crystal (VPFC)model.[Methods]The free energy function of VPFC model was obtained by modifying simple phase field crystal model.The VPFC model was used to study the different periodic crystal profiles in the two-dimensional phases diagram and explore the condition of vacancy presenting.[Results]Different kinds of the two-dimensional periodic crystal structure patterns were obtained by selecting the average a-tomic density values in different phases.[Conclusion]Combining topography of crystal structure with atomic density curve reveals that hexagonal bumps,stripes and hexagonal holes are main structures in the crystal sample.When the average atomic density value is located in the phase diagram of the coexistence zone of the local particles and hexagonal bumps phase,vacancy structures appear in the crystal.Moreover,the vacancies are randomly distributed and their number are related to the atomic density values.