This document discusses nanoscience and nanotechnology concepts. It begins with an introduction to nanoscience topics like quantum effects at the nanoscale. It then discusses various nanostructures such as nanoparticles, nanotubes, thin films and their potential applications. The document also covers magnetic nanostructures such as ferromagnetism and magnetic domains. Measurement techniques like scanning tunneling microscopy are described. Finally, the document discusses thin film fabrication and the giant magnetoresistance effect in multilayer thin films.

1. NANOSCIENCE NANOTECHNOLOGY Walkiria Eyre [email_address]

3. Nanoscience Fisics Engeneering Biology Chemistry Basic life processes Chemical reactions Medicine Classical Fisics Quantum Fisics Smart materials Technological aplications

12. IBM Logo xenon atoms on nickel substract

15. STM From: http://en.wikipedia.org/wiki/Scanning_tunnelling_microscope

24. Process: From: http://www.almaden.ibm.com/vis/stm/gallery.html

25. Examples: From: http://www.almaden.ibm.com/vis/stm/gallery.html

28. A typical configuration for a quantum well (AlIn)GaN LED on a sapphire substrate. Epitaxial layer thicknesses are exaggerated for clarity and are not to scale. From: http://www.mtmi.vu.lt/pfk/funkc_dariniai/diod/led.htm

30. “ Lead selenide (PbSe) quantum dots like the ones in this image, <10nm in size, emit light in the visible regime (~1 to 3eV). The nanoparticles in this scanning tunneling electron micrograph are similar to those in the colorful photograph of CdSe quantum dot containing material. (Micrograph courtesy of Mick Thomas, Cornell University) ” From: http://instruct1.cit.cornell.edu/courses/comm494-nano/working_version/3article.htm

31. The emission from quantum dots is tuned by changing the particle size. These quantum dot solids, containing CdSe nanocrystals dispersed in a polymer matrix, span the visible spectrum when excited with ultraviolet light. For scale, containers are ~ 1 cm in diameter. From: http://instruct1.cit.cornell.edu/courses/comm494-nano/working_version/3article.htm

33. “ Scanning tunneling microscope (STM) image of a silver surface with adsorbed potassium atoms and two C-60 buckyballs. Using the STM tip to drag one of the buckyballs around the surface, UC Berkeley researchers were able to pick up single potassium atoms at a time, subtly altering the buckyball's electronic properties with each addition. Credit: Michael Crommie/UC Berkeley. (Image courtesy of Science) ” From: http://www.nanotech-now.com/ucb-release-03112004.htm

38. CNT

44. MAGNETIC NANOSTRUCTURES

47. Magnetic moment SPIN ( angular moment) *charge* Magnetic Moment

48. Magnetic Moment

50. MAGNETIZATION Alignment of electrons due to the field

56. Interesting effects: From: http://en.wikipedia.org/wiki/Diamagnetism

62. Magnetic Domains The domains are delineated with colloidal iron oxide particles FOTOMICROGRAFY (Bell Telephone Laboratories) From: http://www.feiradeciencias.com.br/sala13/13_38.asp

67. Hysteresis Loop From: http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/imgsol/hyloop.gif

68. Definitions: From: http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/imgsol/coercivity.gif

70. Magnetic Behavior Configuration of minimum potential energy Magnetic domains with random orientation size temperature

78. Ph otomicrogra phy of SBN -s trontium b arium n iobate - thin films .

79. From: http://www.liec.ufscar.br/ceramica/index.html

87. T H E E N D !