Expose students to research grade instrumentation at an early level

1. Including Nanoscale Investigations in Undergraduate Physics Laboratories at all Levels of the Curriculum Kurt Vandervoort, Asif Hyder, Stephanie Barker and Raul Torrico California State Polytechnic University, Pomona, CA Funding for this project was provided by the National Science Foundation Nanotechnology Undergraduate Education program, award # 0406533.

2. Project Goal Expose students to research grade instrumentation at an early level • Develop SPM modules for undergraduate physics labs. Project Purpose • Introduce concepts at successive stages of complexity • Demonstrate utility of physics through cross-disciplinary activities Equipment Universal Scanning Probe Microscope from Quesant Instruments

3. Nanoscale Measurements Module • Existing Experiment: Measurements and Uncertainty • Perform careful measurements using rulers, calipers and balances • Record uncertainties and propagate errors • Compare densities of different materials • Additional AFM Module Objectives • Expose students to the range of length scales available to technology • Obtain practice in unit conversions over several orders of magnitude

4. 5 X 5 mm2 image of a non-recordable CD Calculation to yield memory storage capacity on disk:

5. UHV low-temperature STM image of Cu (111) surface* 3 nm *From A. Yazdani’s Lab, Dept. Physics, UIUC Calculation to yield density of copper:

6. Geometrical Optics Module • Existing Experiment: Geometrical Optics • Observe the interaction of light with prisms, mirrors and lenses • Draw ray diagrams to determine image locations • Additional AFM Module Objectives • Examine rough/smooth surfaces visually and with the AFM • Verify microscopic criteria defining limit for geometrical optics

7. Gold Plated Slides Exhibiting Diffuse and Specular Reflection

8. AFM Image of Specular Reflective Surface

9. Cross-Section of Specular Reflective Surface • Height variation of surface features ~ 10 nm • Height variation << lvisible (400-700 nm)

10. AFM Image of Diffuse Reflective Surface

11. Cross-Section of Diffuse Reflective Surface • Height variation of surface features ~ 2000 nm • Height variation >> lvisible (400-700 nm)

12. Magnetic Fields Module • Existing Experiment: Magnetic Field of a Solenoid • Measure the magnetic field profiles of short and long solenoids • Compare measured results to theory • Additional AFM Module Objectives • View a microscopic image of the magnetic domains on a zip disk • Verify enormous memory capacity of a zip disk

13. 40 X 40 mm2 MFM image of a zip disk Calculation to yield memory storage capacity on disk:

14. Spectroscopy Module • Existing Experiment: Spectroscopy • Observe diffraction pattern from a gas discharge lamp. • Identify specific element from its characteristic spectrum. • Additional AFM Module Objectives • View AFM image of the diffraction grating and compare its actual features to original assumptions about the grating construction.

15. AFM Image of a Diffraction Grating • The grating is not a series of slits, but a series of angled grooves. • Groove spacing ~ 1600 nm, within 5% of specifications (600 lines/mm).

16. Diffraction Grating Cross-section Blaze angle (shallower angle) ~ 23o

17. Blazed Diffraction Gratings groove surface sin-1(nsinqB) qB m = 2 back of grating m = 1 m = 0 m = -1 m = -2 qB • Blaze condition: sin-1(n sin θB) – θB = θm

18. Microwave Optics Module • Existing Experiment: Properties of Microwaves • Gain familiarity with microwave techniques and equipment. • Observe properties for large wavelength em radiation. • Additional AFM Module Objectives • Observe effects of a macroscopic blazed diffraction grating on a double-slit interference pattern.

19. Plates Grating + T q - R Setup for the Microwave Experiment

20. The Macroscopic Diffraction Grating

21. Results for the Microwave Experiment(Slit width = 4 cm; Slit separation = 6 cm) w/out grating (open squares) with grating (solid squares) Center of diffraction envelope shifted to the m = -1 peak.

22. Adaptation to Junior/Senior Level Laboratories Cross-section of Compact Disk • Row spacing ~ 1500 nm  Reflective diffraction grating. • Average bump height ~ 125 nm

23. reflection from bump reflection from flat area Laser spot polycarbonate material Bump Top View Side View Using Destructive Interference to Read a CD

24. Expected Height of CD Bumps • λ0 ≡ wavelength of laser (in air) = 780 nm • λ ≡ wavelength in polycarbonate layer • n ≡ index of refraction for polycarbonate layer = 1.56 • λ = λ0/n = 500 nm • λ/4 = 125 nm

25. Other Modules • Nanoscale Friction Module • Electrostatics Module • Physical Optics Module References: Kurt Vandervoort, Asif Hyder, Stephanie Barker, and Raul Torrico, "Including Nanoscale Investigations in Undergraduate Physics Laboratories at all Levels of the Curriculum," Proceedings of the 2006 Spring Meeting of the Materials Research Society, in press (2006). K. G. Vandervoort, S. L. Adams, and A. M. Hyder, "Revealing the blaze angle: a simple experiment for visualizing diffraction effects using microscopic and macroscopic gratings," Am. J. Phys., in press (2006).