ENGRI111_HW5 - Yuri Andrade Sylvester ENGRI 111...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Yuri Andrade Sylvester November 12, 2004 ENGRI 111 [email protected] Problem Set #5 Option I 1. Compare and contrast the STM with the AFM. Include a) operating principle, b) type of materials appropriate for analysis, and c) ambient conditions required for analysis. Scanning Tunneling Microscopy works under three basic principles: the piezoelectric effect, feedback loop, and quantum mechanical tunneling. The STM functions by bringing a probe near the surface of the sample and passing an electron voltage differential across it. This piezoelectric probe, a material that forms dipoles charges when compressed, takes advantage of the wave property of light to read an electron signal across a very thin layer (sample). The “tunneling” that is created is due to the probability that the electron beam will go through the thing layer (however, the beam’s amplitude is reduced—this is what creates the tunneling effect). Finally, as the piezo head is brought close to the sample, there are two ways to create an image out of it.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern