System for imaging and detecting threshold phenomena associated with and/or atomic or molecular spectra of a substance by reflection of an AC electrical signal
Patent 5281814 Issued on January 25, 1994. Estimated Expiration Date: November 20, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
250/306, INSPECTION OF SOLIDS OR LIQUIDS BY CHARGED PARTICLES204/400, Analysis and testing204/412, Three or more electrodes205/790.5, For properties of solid material (e.g., surface area, etc.)250/307Methods
A microwave sweep oscillator is used to apply an AC signal from the probe tip of a scanning tunneling microscope to a sample, and the reflected signal from the sample is measured by a microwave spectrum/network analyzer, or another device capable of measuring amplitude versus frequency. The frequency of the signal applied by the oscillator may be swept across a spectrum and the optimum frequency of the spectrum is determined so that an improved image of the surface of a sample may be obtained. The spectrum of a known substance may also be recorded and used as a signature for identifying components of an unknown substance by comparison. When the amplitude of the AC signal applied is increased, a sudden change in the reThis invention was made with support from the National Science Foundation, United States Government, under Grant No. CHE-9158375. The government has rights in this invention.
Other References
G. Kochanski, "Nonlinear Alternating-Current Tunneling Microscopy", (AT&T Preprint (Aug. 17, 1988), published in Physical Review Letters, 62 (19):2285-2288 (May 8, 1989)
W. Seifert et al., "Scanning Tunneling Microscopy At Microwave Frequencies," Ultramicroscopy 42-44; 379-387 (1992)
W. Seifert et al., "Scanning Tunneling Microscopy at Microwave Frequencies," Korrigierte Version (Nov. 6, 1991) published in Ultramicroscopy 42-44; 379-387 (1992)
D. Anselmetti et al., H.-J. Guntherodt R. Weisendanger (Eds.) "Scanning Tunneling Microscopy I," pp. 5-6
L. Arnold et al., "Laser-Frequency Mixing Using the Scanning Tunneling Microscope," J. Vac. Sci. Technol., A, 6(2): 466-469 (Mar./Apr. 1988)
L. Arnold et al., "Laser-Frequency Mixing in the Junction of a Scanning Tunneling Microscope," Appl. Phys. Lett., 51(11):786-788 (Sep. 14, 1987)
M. Volcker et al., "Laser-Driven Scanning Tunneling Microscope," Phys. Rev. Lett., 66(13):1717-1720 (Apr. 1, 1991)
D. Cahill et al., "Scanning Tunneling Microscopy of Photoexcited Carriers at the Si(001) Surface," J. Vac. Sci. Technol., B, 9(2):564-567 (Mar./Apr. 1991)
R. Hamers et al., "Atomically Resolved Carrier Recombination at Si (111)-(7×7) Surfaces," Phys. Rev. Lett., 64(9):1051-1054 (Feb. 26, 1990)
Y. Kuk et al., "Optical Interactions in the Junction of a Scanning Tunneling Microscope," published in Phys. Rev. Lett., 65(4):456-459 (1990)
K. Likharev, "Correlated Discrete Transfer of Single Electrons In Ultrasmall Tunnel Junctions," IBM J. Res. Develop., 32(1):144-158 (Jan. 1988)
K. Likharev et al., "Single Electronics," Scientific American, Jun. 1992
C. Andrieux et al., "Ultramicroelectrodes: Cyclic Voltammetry Above One Million V s1 ", J. Electroanal. Chem., 248:447-450 (1988)
R. Wightman et al., "High-Speed Cyclic Voltammetry," Acc. Chem. Res., 23:64-70 (1990)
"Near-Field Optics: Microscopy, Spectroscopy, and Surface Modification Beyond the Diffraction Limit," by Betzig et al., Science, vol. 257, pp. 189-195, Jul. 1992
"Breaking the Diffraction Barrier: Optical Microscopy on a Nanometric Scale," by Betzig et al., Science, vol. 251, pp. 1468-1470, Nov. 30, 1990
"Scanning Surface Harmonic Microscopy: Scanning Probe Microscopy Based on Microwave Field-Induced Harmonic Generation," by Michel et al., Rev. Sci. Instrum., 63(9):4080-4085, Sep. 199
November 20, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
