Anatoly E. Rokhvarger (Brooklyn, NY) and Lubov A Chigirinsky (Brooklyn, NY) reveal a cost effective method to produce sintered ceramic composite leads with superconductive nano-architecture by ceramic-silicone processing (CSP) in U.S. Patent 7,632,784.
A sintered high temperature superconducting (HTS) ceramic electric lead formed as three-dimensional (3D) HTS macro-ceramic solid product with honeycomb-like superconductive nano-architecture is comprised of substantially uniformly aligned nano-size HTS ceramic crystal grains, silicate glass nano-thick films, and nano-size silver and/or inorganic dots that locate in nano-thick boundary areas of the superconductor ceramic crystal grains, and the nano-size films or dots provide honeycomb-like 3D nano-size network within the 3D HTS macro-ceramic solid product or HTS ceramic lead, and the electric lead is superconducting at liquid nitrogen cooling temperature. The superconductive nano-architecture facilitates or controls substantially the higher electro-magnetic and consumable mechanical properties, reliability and durability of the HTS ceramic electric leads.
High temperature superconductor (HTS) macro material and electrical current leads from this material can be produced employing recently invented ceramic-silicone processing method (CSP)1-6. HTS-CSP nanotechnology provides cost-effective production of superconducting ceramic wire and various electric current leads for everyday industrial application at inexpensive liquid nitrogen temperature using off-the-shelf-available superconductor ceramic fine powder particles, such as YBCO ceramics, and standard chemicals including an inexpensive silicone polymer additive and toluene solvent with a small percentage of silver powder dope.
Rokhvarger and Chigirinsky have determined that superconductive behavior, mechanical, durability and JA/cm2 characteristics of HTS-CSP macro leads can be controlled and improved by controlling and improving nano-scale architecture of the ceramic macro products. The nano-architecture is the result of the chemically controlled self-assembling of the three dimensional nano-structure, which meets a set of suggestions of controversial and incomplete Nobel Prize winning physical superconducting theories that considered the collective behavior of the solid and integral compacted mixture comprised of two pluralities--superconductor and non-superconductor nano-size components.
Rokhvarger and Chigirinsky have developed the sintered ceramic composite lead with 3D superconductive nano-architecture and a method of production of the lead, comprising the silicone additive tailored thermo-chemical nanofabrication of the 3D superconductive nano-architecture comprising:
(A) a physical-chemical phase composition consisting of: nano-size superconductor ceramic grains composed of crystals and forming a basic phase elements; additional phase elements constituting nano-thick multi-oxide silicate glass films distributed within grain boundary areas between said grains; further phase elements selected from at least one group consisting of nano-size dope particle, modifier particle, and impurities particle groups, and a combination thereof and said further phase elements are distributed within said grain boundary areas between said grains; and
(B) a three dimensional grain-cell nanostructure comprising 3D setting network and consisting of: said crystals with c-axes oriented substantially perpendicular to a direction of an electric current flux in said lead; said crystal grains substantially uniformly aligned in a-b crystallographic planes; and said additional phase elements and said further phase elements caging and framing said nano-size superconductor ceramic grains and forming nano-size cells comprising said grains surrounding by said additional and further phase elements and providing settings of said grains.
In 1986 two IBM scientists received the Nobel Prize in Physics for synthesizing copper-content-multi-oxide ceramic crystals that have vast electric current carrying capability/capacity (JA/cm.sup.2) at a significantly increased and therefore easily achievable cooling temperature, for example, at inexpensive liquid nitrogen (LN) coolant ambience. Indeed, higher electrical current density results in proportionally decreased cross-section and consequently cost, size and weight of the advanced current lead and appliances using this lead. Therefore, since 1986, many scientists and engineers have tried to utilize High Temperature Superconductor (HTS) ceramics in HTS electric wire and other macro leads for the electrical energy transmission and application industries.
When electric current passes through regular (copper) wire the act of overcoming the "normal" resistance has two negative effects--one is that power is consumed as it is needed to overcome the resistance and, in doing that, the other is that heat is generated. Superconductivity of metal alloys (at expensive liquid helium temperature) and single ceramic crystals (at inexpensive liquid nitrogen temperature) means that at certain low temperature electricity can pass through wire or another lead meeting only insignificant (near zero) resistance and heat generation.
While homogeneous metal alloy superconductors can easily scale-up with the same superconductivity, shaped masses of superconductor ceramic nano-crystal pluralities or granular superconductors do not keep superconductivity of the single crystals.
Therefore, to have certain current carrying capability, HTS granular ceramic lead has to be sintered with certain superconductive nano-architecture of the ceramic composite body.
Additionally, material superconductivity should realize three unique phenomena that allow magnetic propulsion (levitation of heavy objects), increased precision of electrical current measurements (much higher sensitivity and precision of electrical and electronic systems and devices), and electrical energy collection and long-term storage using superconductor magnetic energy storage systems.
HTS ceramics are very chemically active, brittle and degrade under environmental influences. These scientific and engineering problems are overcome in their U.S. patented and partly published ceramic-silicone processing (CSP) method and HTS-CSP composite material, which is suitable for cost-effective fabrication of HTS-CSP strands and surface coated and three-dimensional HTS-CSP leads.sup.1-6. Meanwhile, these inventions and publications did not consider nano-structure and nano-architecture of the HTS-CSP material and an influence of said nano-structure and nano-architecture on material quality.
Rokhvarger and Chigirinsky say the newly invented specific superconductive nano-architecture HTS-CSP material and macro leads is "very important," by controlling this superconductive nano-architecture, they can control and improve quality of the HTS-CSP material and leads.