Claims
- 1. A structure comprising a polycrystalline material having an unconstrained surface and at least one feature projecting above the unconstrained surface, the polycrystalline material comprising grains having a size distribution characterized by an average grain size, the feature protecting from the unconstrained surface of the polycrystalline material a distance that is less than or equal to the average grain size of the polycrystalline material.
- 2. A structure according to claim 1, wherein grain fragments are exposed at the unconstrained surface of the polycrystalline material, the feature being the result of grain growth from one of the grain fragments exposed at the unconstrained surface.
- 3. A structure according to claim 1, wherein a plurality of features project above the unconstrained surface of the polycrystalline material.
- 4. A structure according to claim 3, wherein the structure is a digital recording media and information is recorded in reference to the locations of the features on the unconstrained surface of the polycrystalline material.
- 5. A structure according to claim 1, further comprising a constraining material that constrains the polycrystalline material in all directions but one direction, the unconstrained surface of the polycrystalline material being normal to the one direction.
- 6. A structure according to claim 5, wherein the constraining material has a lower coefficient of thermal expansion than the polycrystalline material.
- 7. A structure according to claim 1, wherein the polycrystalline material is chosen from the group consisting of metals, metal alloys and semiconductor materials.
- 8. A structure according to claim 1, wherein the polycrystalline material is chosen from the group consisting of aluminum, copper, tungsten, and alloys thereof.
- 9. A digital recording media comprising a polycrystalline material constrained by a constraining material in all directions but one direction, the constraining material having a lower coefficient of thermal expansion than the polycrystalline material, the polycrystalline material comprising a surface that is normal to the one direction, grain fragments exposed at the surface, and a plurality of nano-scale extruded structures projecting above the surface, the extruded structures being the result of grain growth from grain fragments exposed at the surface, wherein information is recorded in reference to the locations of the extruded structures on the surface of the polycrystalline material.
Parent Case Info
This is a division of application Ser. No. 09/543,377 filed Apr. 5, 2000, now U.S. Pat. No. 6,464,806.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
3673667 |
Loewenstein et al. |
Jul 1972 |
A |
4005255 |
Wagner et al. |
Jan 1977 |
A |
4921549 |
Austin |
May 1990 |
A |
6464806 |
Naeem et al. |
Oct 2002 |
B1 |