کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1528251 | 1511861 | 2006 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: ‘Pop-in’ phenomenon during nanoindentation in epitaxial GaN thin films on c-plane sapphire substrates ‘Pop-in’ phenomenon during nanoindentation in epitaxial GaN thin films on c-plane sapphire substrates](/preview/png/1528251.png)
Nanoindentation studies have been carried out on undoped and doped epitaxial GaN thin films with different thickness (1–4 μm) were grown epitaxially on c-plane sapphire substrate by metalorganic chemical vapor deposition (MOCVD). Multiple discontinuities (so-called ‘pop-in’ events) were observed in the load–indentation depth curve irrespective of the thickness as well as the doping condition. Atomic force microscopy (AFM) studies on the residual indentation impression revealed no micro-cracks even after the indentation beyond the critical depth. The physical mechanism responsible for the ‘pop-in’ was explained by the interaction of the deformed region, produced by the indenter tip, with the pre-existing threading dislocation in the epitaxial GaN thin films.
Journal: Materials Chemistry and Physics - Volume 99, Issues 2–3, 10 October 2006, Pages 410–413