Alkhedher Mohammad, Majid Abdul, Bulut Niyazi, Elkhatib Samah Elsayed
Mechanical and Industrial Engineering Department, Abu Dhabi University, Abu Dhabi 111188, United Arab Emirates.
Department of Physics, University of Gujrat, Gujrat 50700, Pakistan.
Materials (Basel). 2022 May 18;15(10):3599. doi: 10.3390/ma15103599.
The changes in properties of materials upon introduction of impurities is well documented but less is known about the location of foreign atoms in different hosts. This study is carried out with the motivation to explore dopant location in hexagonal GaN using density functional theory based calculations. The dopant site location of the individual dopants Ti, Ce, and Ti-Ce codoped wurtzite GaN was investigated by placing the dopants at cationic lattice sites as well as off-cationic sites along the c-axis. The geometry optimization relaxed individual dopants on cationic Ga sites but in the case of codoping Ce settled at site 7.8% away along [0001 ¯] and Ti adjusted itself at site 14% away along [0001] from regular cationic sites. The analysis of the results indicates that optimized geometry is sensitive to the starting position of the dopants. The magnetic exchange interactions between Ti and Ce ions are responsible for their structural relaxation in the matrix.
引入杂质后材料性质的变化已有充分记录，但对于不同基质中杂质原子的位置却知之甚少。本研究旨在利用基于密度泛函理论的计算方法，探索六方氮化镓中掺杂剂的位置。通过将掺杂剂置于阳离子晶格位置以及沿c轴的非阳离子位置，研究了单个掺杂剂Ti、Ce以及Ti-Ce共掺杂纤锌矿型氮化镓的掺杂位置。几何优化使单个掺杂剂在阳离子Ga位点上松弛，但在共掺杂的情况下，Ce位于沿[0001 ¯]偏离7.8%的位置，Ti则在沿[0001]偏离规则阳离子位点14%的位置自行调整。结果分析表明，优化后的几何结构对掺杂剂的起始位置敏感。Ti和Ce离子之间的磁交换相互作用是它们在基质中结构弛豫的原因。
