What is claimed is:
1. A tip calibration standard for calibrating scanning probe microscope probe tips comprising a carbon nanotube having a length of at least about 1 micron and a diameter of not greater than about 10 nm disposed on a dielectric surface of a grounded, conductive substrate and in connection with a contact mounted on the substrate.
2. The standard of claim 1 wherein the nanotube is metallic.
3. The standard of claim 1 wherein the nanotube is semiconductive.
4. The standard of claim I wherein the nanotube is a single-walled nanotube.
5. The standard of claim 1 wherein the nanotube is a multi-walled nanotube.
6. The standard of claim 1 wherein the substrate is semiconductive.
7. The standard of claim 1 wherein the substrate comprises silicon.
8. The standard of claim 1 wherein the dielectric surface of the substrate has a roughness of no greater than about 3 nm RMS.
9. The standard of claim 1 wherein the contact is metallic and, when mounted on the substrate, extends beyond the surface of the substrate by no more than about 50 nm.
10. The standard of claim 1 wherein the dielectric surface of the substrate has a resistivity sufficient to prevent leakage from the nanotube disposed thereon into the substrate.
11. The standard of claim 1 wherein the nanotube is a single-walled nanotube, the substrate comprises grounded silicon having a surface layer of silicon oxide with a roughness of no greater than about 3 nm RMS.
12. A method for calibrating a scanning probe microscope probe tip mounted on a cantilever in communication with a cantilever deflection detector comprising the steps of:
applying an AC bias to the nanotube standard of claim 1;
measuring with the detector cantilever deflection caused by a scan of the AC-biased standard with the probe tip; and
converting the cantilever deflection data into probe tip data.
13. The method of claim 12 wherein the AC bias is applied directly to the nanotube.
14. The method of claim 12 further comprising the step of computing the probe tip geometry from the probe tip data.
15. The method of claim 12 further comprising the step of computing electrostatic imaging data from the probe tip data.
16. The method of claim 12 further comprising the step of computing the convolution function from the probe tip data.
17. The method of claim 12 further comprising the step of computing the proportionality coefficient between tip capacitance and the deflection data and wherein the diameter of the nanotube is known.
18. The method of claim 12 wherein the voltage of the AC bias on the nanotube is about 50 mV to about 200 mV.
19. The method of claim 12 further comprising the step of computing the probe tip geometry, the electrostatic data, and the convolution function from the probe tip data and wherein the AC bias is applied directly to the nanotube at a voltage of between about 50 mV and about 200 mV, and at a frequency at or near the resonant frequency of the cantilever.
20. The method of claim 19 further comprising the step of computing the proportionality coefficient between tip capacitance and the deflection data and wherein the diameter of the nanotube is known.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An optically active polyphenylacetylene compound substituted by chiral alkoxy groups as represented by the general formula
4
in which R is a chiral alkoxy group having at least 4 carbon atoms including a secondary carbon atom and the subscript n is an integer of 10 or larger.
2. The optically active polyphenylacetylene compound as claimed in claim 1 in which the chiral alkoxy group denoted by R is bonded to the phenyl group at the para position.
3. The optically active polyphenylacetylene compound as claimed in claim 1 which has a pseudo-hexagonal structure and has a superspiral conjugation structure by the electrons due to double bonds.
4. A method for the preparation of the optically active polyphenylacetylene compound as defined in claim 1 which comprises the step of:
bringing an alkoxyphenylacetylene compound represented by the general formula
5
in which R is a chiral alkoxy group having at least 4 carbon atoms including a secondary carbon atom, as dissolved in an organic solvent into contact with a rhodium complex compound to effect polymerization thereof.
5. The method as claimed in claim 4 in which the rhodium complex compound is Rh(norbornadiene)Cl2.
6. The method as claimed in claim 4 in which the organic solvent is an amine compound or an alcohol compound.
7. The method as claimed in claim 4 in which the organic solvent is triethylamine.
8. The method as claimed in claim 4 in which the organic solvent is chloroform.
9. The method as claimed in claim 4 in which the amount of the rhodium complex compound is in the range from {fraction (1100)} to {fraction (1150)} mole per mole of the alkoxyphenylacetylene compound.