In an embodiment, a method includes liberating feed atoms and forming at least one nanotube from the liberated feed atoms. Feed atoms disposed over a front side of a substrate are liberated in response to electromagnetic radiation that propagates from the back side of the substrate, through the substrate, to the front side of the substrate. And, from the liberated feed atoms, at least one nanotube is formed over the front side of the substrate in response to at least one catalyst separate from the substrate and disposed over the front side of the substrate and over the feed atoms.

In an embodiment, a method includes liberating feed atoms and forming at least one nanotube from the liberated feed atoms. Feed atoms disposed over a front side of a substrate are liberated in response to electromagnetic radiation that propagates from the back side of the substrate, through the substrate, to the front side of the substrate. And, from the liberated feed atoms, at least one nanotube is formed over the front side of the substrate in response to at least one catalyst separate from the substrate and disposed over the front side of the substrate and over the feed atoms.

An abrasive particle having an irregular surface, wherein the surface roughness of the particle is less than about 0.95. A method for producing modified abrasive particles, including providing a plurality of abrasive particles, providing a reactive coating on said particles, heating said coated particles; and recovering modified abrasive particles.

An abrasive particle having an irregular surface, wherein the surface roughness of the particle is less than about 0.95. A method for producing modified abrasive particles, including providing a plurality of abrasive particles, providing a reactive coating on said particles, heating said coated particles; and recovering modified abrasive particles.

There is provided a polycrystalline cubic boron nitride containing a cubic boron nitride at a content greater than or equal to 98.5% by volume, the polycrystalline cubic boron nitride having a dislocation density less than or equal to 8×10.sup.15/m.sup.2.

To provide a sintered material having excellent oxidation resistance, as well as excellent abrasion resistance and chipping resistance. A sintered material containing a first compound formed of Ti, Al, Si, O, and N is provided.

It is an object to achieve a resin sheet having high thermal conductance and high dielectric strength. Hexagonal boron nitride powder in accordance with an aspect of the present invention includes hexagonal boron nitride agglomerate particles each including agglomerated hexagonal boron nitride primary particles, and has a specific surface area of not less than 0.5 m.sup.2/g and not more than 5.0 m.sup.2/g. The hexagonal boron nitride primary particles each have a long diameter of not less than 0.6 μm and not more than 4.0 μm and an aspect ratio of not less than 1.5 and not more than 5.0.

It is an object to achieve a resin sheet having high thermal conductance and high dielectric strength. Hexagonal boron nitride powder in accordance with an aspect of the present invention includes hexagonal boron nitride agglomerate particles each including agglomerated hexagonal boron nitride primary particles, and has a specific surface area of not less than 0.5 m.sup.2/g and not more than 5.0 m.sup.2/g. The hexagonal boron nitride primary particles each have a long diameter of not less than 0.6 μm and not more than 4.0 μm and an aspect ratio of not less than 1.5 and not more than 5.0.

A cubic boron nitride sintered material includes: more than or equal to 85 volume % and less than 100 volume % of cubic boron nitride grains; and a remainder of a binder, wherein the binder includes WC, Co and an Al compound, and when a TEM-EDX is used to analyze an interface region including an interface at which the cubic boron nitride grains are adjacent to each other, oxygen exists on a whole or part of the interface, and a width D of a region in which the oxygen exists is more than or equal to 0.1 nm and less than or equal to 10 nm.

A solution is provided comprising boron nitride nanotubes (BNNTs) in a liquid solvent. An optical waveguide, such as an optical fiber, is contacted with the solution so as to form a layer of the solution supported on at least a portion of the optical waveguide. The liquid solvent is then removed from the layer of the solution supported on the optical waveguide in order to form a coating of the BNNTs on the optical waveguide. Further provided is a BNNT coated optical waveguide for use as a sensor.