SOURCE:

Faculty: Physical Sciences
Department: Physics And Industrial Physics

CONTRIBUTORS:

Olisakwe, S.I
Ekpunobi, A. J
Ekwo, P.I

ABSTRACT:

In this research work, six new models were developed and used to study the effects of three different parameters on nanotribology of seven different semiconductors – silicon (Si), germanium (Ge), tin (Sn), zinc sulphide (ZnS), zinc selenide (ZnSe), cadmium sulphide (CdS) and cadmium selenide (CdSe). Jump energy quantum models for high and low ionic energy gaps were developed through a combination of Tomlinson model and bond-orbital model. Using these models, ∆E which is the energy that prevents the tips jump was calculated for all the semiconductors under study. Temperature model was developed through a combination of Tomlinson model and Sang`s equation. Low and high velocity models were developed through transformation and modifications of temperature model. The normal load model was developed through a transformation and modifications of temperature model. The results obtained using jump energy quantum models for high and low ionic energy gaps compare favourably with the values of ∆E obtained using Tomlinson model. Temperature model was used to study the effects of temperature on nanotribology of Si. The results obtained compare favourably with experimental results for Si found in literature. Hence the model was used for other six semiconductors under study and results were generated. Low and high velocity models were used to study the effects of velocity on nanotribology of silicon. The results obtained are in good agreement with experimental results for Si found in literature. Hence these models were used for other six semiconductors under study and results were generated. Normal load model was used to study the effects of normal load on nanotribology of silicon. The results obtained are in reasonable agreement with experimental results for silicon found in literature. Hence this model was also used for the other six semiconductors under study and results were generated. There are no experimental results for the six semiconductors- germanium, tin, zinc sulphide, cadmium sulphide, zinc selenide and cadmium selenide but can be confirmed by experiment. We are therefore predicting the experimental results of these semiconductors for the first time using our models. From this work it was found that: Friction force at nano-level decreases with increase in temperature, friction force decreases with increase in velocity and that friction at nano-level increases with increase in normal load.