Patent US5164595A successfully refreshed from Google Patents.
US5164595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scanning tunneling microscope tips
Assignee: North Carolina State University
•
Filing: 1991-10-25
•
Granted: 1992-11-17
•
Expires: 2011-10-25
Abstract
Abstract A method of fabricating a double-tapered scanning tunneling microscope comprises (a) immersing one end of the tip in a bath of an acidic aqueous etchant solution containing an alkaline earth salt, with the wire positioned substantially perpendicularly to the surface of the solution; and (b) etching the wire at about 25 volts root mean squared (rms) alternating current (ac) until a double-tapered tip is formed thereon. The etching step is preferably followed by a polishing step which comprises (c) providing a thin film of a second acidic aqueous etchant solution containing an alkaline earth salt; then (d) contacting said electrode tip to the thin film: and then (e) etching the tip at about 2 volts rms ac to thereby polish the tip. Also disclosed is a method of inhibiting the formation of carbon on a scanning tunneling microscope tip which comprises (a) positioning a wire in an etchant solution and then (b) etching the wire while excluding carbon dioxide therefrom. Double-tapered scanning tunneling microscope tip comprises of an elongate wire and methods of using the same are also disclosed.
Inventors
- 👤 Inga H. Musselman
- 👤 Phillip E. Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:42
CPC Classifications
G; G01; G01Q; G01Q60/00; G01Q60/10; G01Q60/16; B; B82; B82Y; B82Y35/00; C; C25; C25F; C25F3/00; C25F3/02; C25F3/16; H; H01; H01J; H01J9/00; H01J9/02; H01J9/022; H01J9/025; H01J2201/00; H01J2201/30; H01J2201/304; H01J2201/30446; H01J2201/30453; H01J2201/30457; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/86; Y10S977/861; Y10S977/875; Y10S977/878; Y10S977/888
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
120 words
A double-tapered scanning tunneling microscope tip, comprising: an elongate wire, said wire having a diameter of from about 0.1 to about 0.5 millimeters, said wire formed from platinum, iridium, or a platinum/iridium alloy; an intermediate conical portion formed at one end of said elongate wire; an end conical portion formed at the apex of said intermediate conical portion and axially aligned therewith, with said intermediate conical portion having a cone half angle greater than said end conical portion and with said end conical portion having a cone half angle of from about 5 to about 10 degrees; and a tip formed at the apex of said end conical portion, said tip having a radius of curvature of about 500 Å.
Claim 2
Dependent Claim
120 words
A double-tapered scanning tunneling microscope tip, comprising: an elongate wire, said wire having a diameter of from about 0.1 to about 0.5 millimeters, said wire formed from platinum, iridium, or a platinum/iridium alloy; an intermediate conical portion formed at one end of said elongate wire; an end conical portion formed at the apex of said intermediate conical portion and axially aligned therewith, with said intermediate conical portion having a cone half angle greater than said end conical portion and with said end conical portion having a cone half angle of from about 5 to about 10 degrees; and a tip formed at the apex of said end conical portion, said tip having a radius of curvature of about 500 Å.
Claim 3
Dependent Claim
20 words
A tip according to claim 1, wherein said wire has a diameter of from about 0.20 to about 0.25 millimeters.
Claim 4
Dependent Claim
26 words
A tip according to claim 1, wherein said wire is formed from an alloy consisting essentially of 80% by weight platinum and 20% by weight iridium.
Claim 5
Dependent Claim
19 words
A tip according to claim 1, wherein said end conical portion has a cone half angle of about degrees.
Claim 6
Dependent Claim
21 words
A tip according to claim 1, wherein said end conical portion has a length of about 100 to about 300 microns.
Claim 7
Dependent Claim
164 words
In a method of conducting scanning tunneling microscopy in which a microscope tip is positioned adjacent to the surface of a conducting sample, a voltage applied to the tip, the tip moved across the surface of the sample, and the tunneling current between the tip and the sample detected, the improvement comprising employing a double-tapered scanning tunneling microscope tip, the tip comprising: an elongate wire, said wire having a diameter of from about 0.1 to about 0.5 millimeters; an intermediate conical portion formed at one end of said elongate wire; an end conical portion formed at the apex of said intermediate conical portion and axially aligned therewith, with said intermediate conical portion having a cone half angle greater than said end conical portion and with said end conical, portion having a cone half angle of from about 5 to about 10 degrees; and a tip formed at the apex of said end conical portion, said tip having a radius of curvature of about 500Å.
Claim 8
Dependent Claim
164 words
In a method of conducting scanning tunneling microscopy in which a microscope tip is positioned adjacent to the surface of a conducting sample, a voltage applied to the tip, the tip moved across the surface of the sample, and the tunneling current between the tip and the sample detected, the improvement comprising employing a double-tapered scanning tunneling microscope tip, the tip comprising: an elongate wire, said wire having a diameter of from about 0.1 to about 0.5 millimeters; an intermediate conical portion formed at one end of said elongate wire; an end conical portion formed at the apex of said intermediate conical portion and axially aligned therewith, with said intermediate conical portion having a cone half angle greater than said end conical portion and with said end conical, portion having a cone half angle of from about 5 to about 10 degrees; and a tip formed at the apex of said end conical portion, said tip having a radius of curvature of about 500Å.
Claim 9
Dependent Claim
21 words
A method according to claim 6, wherein said wire is formed from a noble metal or an alloy of noble metals.
Claim 10
Dependent Claim
18 words
A method according to claim 6, wherein said wire is formed from platinum, iridium, or a platinum/iridium alloy.
Claim 11
Dependent Claim
20 words
A method according to claim 6, wherein said wire has a diameter of from about 0.2 to about 0.25 millimeters.
Claim 12
Dependent Claim
26 words
A method according to claim 6, wherein said wire is formed from an alloy consisting essentially of 80% by weight platinum and 20% by weight iridium.
Claim 13
Dependent Claim
20 words
A method according to claim 6, wherein said end conical portion has a cone half angle of about 8 degrees.
Claim 14
Dependent Claim
21 words
A method according to claim 6, wherein said end conical portion has a length of about 100 to about 300 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |