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Nanotechnology

Nanotechnology, under the guidance of Prof. Dr. S. Taha, Vice Dean for Postgraduate Studies and Research Affairs at the Faculty of Science, Fayoum University, Egypt, delves into the fascinating world of nanocrystals. These tiny structures, measuring just a few nanometers, exhibit unique electronic, magnetic, and optical properties due to their size. This phenomenon, known as quantum confinement, leads to discrete energy levels that enable novel applications in electronics. The study of nano-sized clusters reveals their ability to self-assemble into ordered arrays, paving the way for advanced materials and innovative technologies.

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Nanotechnology

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  1. Nanotechnology • Prof. Dr. S. Taha • Physics department • Vice Dean for Postgraduate • Studies and Research Affairs • Faculty of Science • Fayoum university • Egypt

  2. 1- definition of nano Particles . • A nano cluster is a tiny chunk of the bulk measuring a few nanometers with a Finite number of atoms in it. • 2- Physical Properties of Nanocrystals . • a- The electronic Structure of a nano crystal Critically depends on its Size . • The electronic level are not Continuous as in bulk materials , but discrete , due to the confinement of the electron wave - function because of the Physical dimensions of the Particles . This Phenomenon is Called quantum confinement, therefore , nanocrystals are also Known as quantum dots.

  3. b- The average electronic energy level Spacing of Successive quantum levels , Known as the so-Called Kubo gap , is given by • n3/ EF4 = δ • c- The resultant discreteness of energy levels . ( the nano crystals Can be discretely charged with electrons ) . ( i . e ) nano crystal Carrying an extra electrons can exhibit Properties different from those of a neutral species also brings about fundamental changes in the characteristic Spectral features of the nano particles , especially those related to the valence band .

  4. 3- The nano Sized clusters display a remarkable tendency to remain Single – Crystalline and hence are also called nano crystals . In addition , nano crystals Possess a high surface area : A great fraction of atoms in nanocrystal is on its surface . • The nano crystals is their Size – dependent Properties ( i . e ) the electronic , magnetic , and optical Properties of a nano crystal depend on its size ( quantum size effects ) .

  5. 4- a - The nano crystals akin to covalent systems Self-assemble into ordered arrays in one , two and three dimensions under the right conditions . • b- Lattices of nano crystals consist of interacting nano crystals and may exhibit novel Properties arising out of such interaction . • c- Thus , the ability to engineer such assemblies extends the reach of current lattices of nano crystals and holds promise for a new generation of electronics of the nanoworld .

  6. 5- size control • 6- Shape control .

  7. 7- Example CNT .

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