{"title":"Strain induced phase transitions and hysteresis in aluminium nitride: a density functional theory study.","authors":"O Namir, J Chen, I Belabbas","doi":"10.1088/1361-648X/ad8852","DOIUrl":null,"url":null,"abstract":"<p><p>Computer atomistic simulations based on density functional theory were carried out to investigate strain induced phase transitions in aluminium nitride (AlN). The wurtzite to graphitic and graphitic to wurtzite transformations were investigated at the atomic level and their physical origins were identified. Both phase transitions were found to be of the first order. The wurtzite to graphitic phase transition takes place in the tensile regime at a strain value of +7%. The driving force for this transformation was identified to be an elastic instability induced by tensile strain. A hysteresis was demonstrated where the graphitic structure is separated from the wurtzite by a kinetic energy barrier. The origin of the observed hysteresis is due to the asymmetry of bond formation and bond breaking associated with the wurtzite to graphitic and graphitic to wurtzite transitions, respectively. A dynamic instability taking place at +3%, along the graphitic path, prevents the hysteresis to fully occur. The possible occurrence of the hysteresis has then to be taken into account when growing the graphitic phase by heteroepitaxy. Otherwise, maintaining the graphitic structure at low strain, through the hysteresis, offers new possibilities in the development of novel future applications.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physics: Condensed Matter","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1361-648X/ad8852","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
Computer atomistic simulations based on density functional theory were carried out to investigate strain induced phase transitions in aluminium nitride (AlN). The wurtzite to graphitic and graphitic to wurtzite transformations were investigated at the atomic level and their physical origins were identified. Both phase transitions were found to be of the first order. The wurtzite to graphitic phase transition takes place in the tensile regime at a strain value of +7%. The driving force for this transformation was identified to be an elastic instability induced by tensile strain. A hysteresis was demonstrated where the graphitic structure is separated from the wurtzite by a kinetic energy barrier. The origin of the observed hysteresis is due to the asymmetry of bond formation and bond breaking associated with the wurtzite to graphitic and graphitic to wurtzite transitions, respectively. A dynamic instability taking place at +3%, along the graphitic path, prevents the hysteresis to fully occur. The possible occurrence of the hysteresis has then to be taken into account when growing the graphitic phase by heteroepitaxy. Otherwise, maintaining the graphitic structure at low strain, through the hysteresis, offers new possibilities in the development of novel future applications.
期刊介绍:
Journal of Physics: Condensed Matter covers the whole of condensed matter physics including soft condensed matter and nanostructures. Papers may report experimental, theoretical and simulation studies. Note that papers must contain fundamental condensed matter science: papers reporting methods of materials preparation or properties of materials without novel condensed matter content will not be accepted.