materials science

Nanowires Grown by Beam Epitaxy

Registration: 
Open to all.
Date: 
04 December 2008
Time: 
11 am
Venue: 
Centre for Solid State Physics, University of the Punjab, Quaid-e-Azam Campus, Lahore
Abstract: 

Semiconductor nanowires (NWs) are attracting wide interest due to their unique physical properties and potential for application in nanodevices. NWs can be obtained by a number of growth methods, and their highly anisotropic growth originates by the presence of a metal particle, the catalyst, that determines the position and the diameter of the nanostructure. The most widely used catalyst is gold. The growth mechanism of catalyst assisted nanowires involves the incorporation of material both impinging on the catalyst particle and diffusing from the free substrate surface to the sidewalls of the wire. The interplay of these two phenomena is critical especially for the growth of alloy semiconductor compound NWs and one dimensional (1-D) heterostructure. Difference in the surface mobility between the constituents could give compositional inhomogeneities in alloy NWs and degradation of the interface sharpness in 1-D heterostructure. The systematic presence of a metal particle at the NWs tip could be exploited in single NW devices. Moreover, one of the most interesting characteristic of the III-V NWs grown by catalyst assisted self assembling is the peculiarity of having an hexagonal lattice structure (wurtzite), while their bulk and epitaxial parent materials have the cubic structure (zinc blend). In our laboratory we have synthesized GaAs NWs by molecular beam epitaxy (MBE) either using a thin gold, manganese, Ga layer as the growth catalyst or without any catalyst. In this talk some of the basics of NWs, their growth and potential applications will be covered.

Resource People: 
Presenter
Fouzia Jabeen
Elletra Synchrotrone, University of Trieste, Italy.

National Workshop on Crystal Structure Determination Using Powder X-ray Diffraction

Registration: 
Registration is required.
Date: 
15 August 2007
Time: 
09:00 am
Venue: 
Centre for Solid State Physics, University of the Punjab, Quaid-e-Azam Campus, Lahore
Abstract: 

Powder X-Ray Diffraction is now a common technique used in the structure determination of different crystals. Read this Article on the Workshop on structure determination using powder X-ray diffraction.

 

Resource People: 
Presenter
Dr. Falak Sher
Pakistan Institute of Engineering and Allied Sciences (PIEAS), Islamabad
Presenter
Dr. N.M. Butt
Chairman Pakistan Science Foundation, Islamabad
Presenter
Dr. Umair Manzoor
Department of Physics, COMSATS, Islamabad
Presenter
Dr. Saadat Anwar Siddiqi
Centre for Solid State Physics, Punjab University, Lahore
Presenter
Dr. Arshad S. Bhatti
Department of Physics, COMSATS, Islamabad
Presenter
Dr. Sabieh Anwar
School of Science and Engineering, LUMS, Lahore
Presenter
Dr . Menges Goetz
Bruker-AXS, Germany

Ceramic Nano-particles

From Synthesis to Applications
Registration: 
Open to all.
Date: 
21 April, 2002
Time: 
11:00 am
Venue: 
Centre for Solid State Physics, University of the Punjab, Quaid-e-Azam Campus, Lahore
Abstract: 

This seminar will introduce the basics of nanotechnology. Alongwith the fundamentals, it will overview current research trends and the underlying problems in nanotechnology. Focus will be on ceramic nano-particles, such as their synthesis routes (including thermal hydrolysis, hydrothermal processes and solid state reaction). Some applications of nano-ceramics will also be mentioned.

Resource People: 
Speaker
Umair Manzoor
Department of Materials Science and Engineering, Korea Advanced Institute of Engineering Science and Technology, South Korea.

Introduction to Material Science and a Case Study of Biomaterials

Registration: 
Open to all.
Date: 
26 March 1998
Time: 
11:00 am
Venue: 
New Lecture Theater, University of Engineering and Technology (UET), Lahore
Resource People: 
Speaker
Muhammad Sabieh Anwar
Electrical Engineering Department, University of Engineering and Technology (UET), Lahore