{"title":"Diffraction Artefacts from Twins and Stacking Faults, and the Mirage of Hexagonal, Polytypes or Other Supersuperstructures","authors":"C. Cayron","doi":"10.2139/ssrn.3714494","DOIUrl":null,"url":null,"abstract":"Recently, a hexagonal phase has been reported in high carbon steels in several studies. Here, we show that the electron microscopy results used in these studies were erroneously interpreted. The extra-spots in the diffraction patterns and the odd contrasts in the high resolution images are not those a superstructure but result from double diffraction and streaking effects due to the presence of twins and stacking faults. We point out a similar unfortunate misunderstanding of these effects in papers reporting the existence of a 9R structure in aluminium or copper, or exotic forms of carbon in diamonds.","PeriodicalId":438337,"journal":{"name":"EngRN: Metals & Alloys (Topic)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"EngRN: Metals & Alloys (Topic)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2139/ssrn.3714494","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Recently, a hexagonal phase has been reported in high carbon steels in several studies. Here, we show that the electron microscopy results used in these studies were erroneously interpreted. The extra-spots in the diffraction patterns and the odd contrasts in the high resolution images are not those a superstructure but result from double diffraction and streaking effects due to the presence of twins and stacking faults. We point out a similar unfortunate misunderstanding of these effects in papers reporting the existence of a 9R structure in aluminium or copper, or exotic forms of carbon in diamonds.