Nanoindentation-induced structural phase transformations in crystalline and amorphous germanium Online publication date: Sat, 08-Aug-2009
by Maha M.O. Khayyat, M. Munawar Chaudhri, G. Patriarche, E. Le Bourhis
International Journal of Nano and Biomaterials (IJNBM), Vol. 2, No. 1/2/3/4/5, 2009
Abstract: During hardness indentation with a diamond indenter, materials are subjected to highly localised pressures. These pressures may cause a complete change of atomic arrangement of the material within the indented zone. This paper reports that when a Berkovich or Vickers nanoindenter is loaded onto a submicrometer thick film of amorphous germanium (a-Ge) and germanium single crystals (Ge-I), they undergo structural phase transitions. These observations are based on Raman scattering investigations, and high resolution transmission electron microscopy. The results show that a-Ge transforms to a face centred cubic (FCC) Ge-I, and simple tetragonal ST12-phase (Ge-III). On the other hand, single crystals of germanium Ge-I transforms to Ge-III and a-Ge phases. It also shows that Ge-III phase is sensitive to the power of the exciting laser beam. It has been shown that structural phase transitions occur at a nanozone close to the indenter tip, where the plastic strain is the highest.
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Nano and Biomaterials (IJNBM):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email subs@inderscience.com
Our Blog 
Follow us on Twitter 
Visit us on Facebook