Phase transformations induced in relaxed amorphous silicon by indentation at room temperature
نویسندگان
چکیده
The deformation behavior of self-ion-implanted amorphous-Si (a-Si) has been studied using spherical nanoindentation in both relaxed (annealed) and unrelaxed (as-implanted) a-Si. Interestingly, phase transformations were clearly observed in the relaxed state, with the load–unload curves from these samples displaying characteristic discontinuities and cross-sectional transmission electron microscopy images indicating the presence of high-pressure crystalline phases Si-III and Si-XII following pressure release. Thus, an amorphous to crystalline phase transformation has been induced by indentation at room temperature. In contrast, no evidence of a phase transformation was observed in unrelaxed a-Si, which appeared to deform via plastic flow of the amorphous phase. Furthermore, in situ electrical measurements clearly indicate the presence of a metallic Si phase during loading of relaxed a-Si but no such behavior was observed for unrelaxed a-Si © 2004 American Institute of Physics. [DOI: 10.1063/1.1832757]
منابع مشابه
Phase transformations induced by spherical indentation in ion-implanted amorphous silicon
The deformation behavior of ion-implanted unrelaxed and annealed ion-implanted relaxed amorphous silicon a-Si under spherical indentation at room temperature has been investigated. It has been found that the mode of deformation depends critically on both the preparation of the amorphous film and the scale of the mechanical deformation. Ex situ measurements, such as Raman microspectroscopy and c...
متن کاملEffect of hydrogen on nanoindentation-induced phase transformations in amorphous silicon
The effect of local hydrogen concentration on nanoindentation-induced phase transformations has been investigated in ion-implanted amorphous silicon a-Si . Elevated concentrations of H ranging from 5 1018 to 5 1020 cm−3, over the depth of indentation-induced phase transformed zones have been formed in the a-Si by H ion-implantation. Indentation has been performed under conditions that result in...
متن کاملIn situ spectroscopic study of the plastic deformation of amorphous silicon under non-hydrostatic conditions induced by indentation.
Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique. Quantitative analyses of the generated in situ Raman maps provide unique, new insight into the phase behavior of as-implanted a-Si. In particular, the ...
متن کاملPolycrystalline Silicon Produced by Joule-Heating Induced Crystallization
An electric field was applied to a conductive layer to induce Joule heating in order to generate the intense heat needed to carry out the crystallization of amorphous silicon. Complete crystallization was observed via Joule heating under typical processing conditions. Crystallization was accomplished throughout the sample within the range of microseconds of the heating, thus demonstrating the p...
متن کاملSpontaneous phase and morphology transformations of anodized titania nanotubes induced by water at room temperature.
We report a spontaneous phase transformation of titania nanotubes induced by water at room temperature, which enables the as-anodized amorphous nanotubes to be crystallized into anatase mesoporous nanowires without any other post-treatments. These mesoporous TiO(2) nanomaterials have a markedly improved surface area, about 5.5 times than that of the as-anodized TiO(2) nanotubes, resulting in a ...
متن کامل