{"title":"氮化铝单晶中不同极性表面的稳定性研究","authors":"Zhao Liu, Wenliang Li, Zuoyan Qin, Lei Jin, Zhenhua Sun, Honglei Wu","doi":"10.3390/cryst14040337","DOIUrl":null,"url":null,"abstract":"Wurtzite aluminum nitride (AlN) crystal has a non-centrosymmetric crystal structure with only a single axis of symmetry. In an AlN crystal, the electronegativity difference between the Al atom and N atom leads to a distortion of electron cloud distribution outside the nucleus and a spontaneous polarization (SP) along the c-axis direction. The N-polar surface along the directions of [000-1] has higher surface energy than the Al-polar surface along the directions of [0001]. Due to the different atomic arrangement, Al atoms on the Al-polar surface bond with O and OH− in the environment to generate Al2O3·xH2O, which prevents the reaction from occurring inside the crystal. After the Al2O3·xH2O dissolve in an alkaline environment, N atoms have three dangling bonds exposed on the surface, which can also protect OH− from destroying the internal Al-N bonds, so the Al-polar surface is more stable than the N-polar surface.","PeriodicalId":505131,"journal":{"name":"Crystals","volume":"12 23","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Research on the Stability of Different Polar Surfaces in Aluminum Nitride Single Crystals\",\"authors\":\"Zhao Liu, Wenliang Li, Zuoyan Qin, Lei Jin, Zhenhua Sun, Honglei Wu\",\"doi\":\"10.3390/cryst14040337\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Wurtzite aluminum nitride (AlN) crystal has a non-centrosymmetric crystal structure with only a single axis of symmetry. In an AlN crystal, the electronegativity difference between the Al atom and N atom leads to a distortion of electron cloud distribution outside the nucleus and a spontaneous polarization (SP) along the c-axis direction. The N-polar surface along the directions of [000-1] has higher surface energy than the Al-polar surface along the directions of [0001]. Due to the different atomic arrangement, Al atoms on the Al-polar surface bond with O and OH− in the environment to generate Al2O3·xH2O, which prevents the reaction from occurring inside the crystal. After the Al2O3·xH2O dissolve in an alkaline environment, N atoms have three dangling bonds exposed on the surface, which can also protect OH− from destroying the internal Al-N bonds, so the Al-polar surface is more stable than the N-polar surface.\",\"PeriodicalId\":505131,\"journal\":{\"name\":\"Crystals\",\"volume\":\"12 23\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-03-31\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Crystals\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3390/cryst14040337\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Crystals","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/cryst14040337","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
伍兹氮化铝(AlN)晶体是一种非中心对称晶体结构,只有一条对称轴。在氮化铝晶体中,铝原子和 N 原子间的电负性差异导致核外电子云分布扭曲,并沿 c 轴方向产生自发极化 (SP)。沿[000-1]方向的 N 极表面比沿[0001]方向的 Al 极表面具有更高的表面能。由于原子排列不同,Al 极表面上的 Al 原子与环境中的 O 和 OH- 结合生成 Al2O3-xH2O,从而阻止了反应在晶体内部发生。Al2O3-xH2O 在碱性环境中溶解后,N 原子有三个悬键暴露在表面,这也能保护 OH- 不破坏内部的 Al-N 键,因此 Al 极表面比 N 极表面更稳定。
Research on the Stability of Different Polar Surfaces in Aluminum Nitride Single Crystals
Wurtzite aluminum nitride (AlN) crystal has a non-centrosymmetric crystal structure with only a single axis of symmetry. In an AlN crystal, the electronegativity difference between the Al atom and N atom leads to a distortion of electron cloud distribution outside the nucleus and a spontaneous polarization (SP) along the c-axis direction. The N-polar surface along the directions of [000-1] has higher surface energy than the Al-polar surface along the directions of [0001]. Due to the different atomic arrangement, Al atoms on the Al-polar surface bond with O and OH− in the environment to generate Al2O3·xH2O, which prevents the reaction from occurring inside the crystal. After the Al2O3·xH2O dissolve in an alkaline environment, N atoms have three dangling bonds exposed on the surface, which can also protect OH− from destroying the internal Al-N bonds, so the Al-polar surface is more stable than the N-polar surface.