Реферат: Superconductors Essay Research Paper Type II superconductors

Название: Superconductors Essay Research Paper Type II superconductors
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Superconductors Essay, Research Paper

Type II superconductors are much different from Type I superconductors

because Type II superconductors gradually become superconducting

materials as opposed to at a certain temperature as Type I superconductors

do. As opposed to Type I superconductors, Type II superconductors are

mostly metallic compounds and alloys. The major exceptions to this are

the elements niobium, technetium, and vanadium. These are pure elements

that are Type II superconductors at sufficiently low temperatures.

Type II superconductors have much higher critical temperatures than Type I

superconductors. Also opposite to Type I superconductors, Type II

superconductors do allow some penetration by an external magnetic field.

Scientists are still trying to understand what makes Type II

superconductors have critical temperatures so much higher than those of the Type I

superconductors. It is thought that it is related to the planar

layering in the structure of the crystal. The highest temperature Type II

superconductor is a perovskite with a critical temperature of 138 K, an

incredibly high temperature for a superconductor. This compound is

Hg0.8Tl0.2Ba2Ca2Cu3O8.33.

The final type of superconductors is the atypical superconductors.

These superconductors are made by fullerides. Fullerides or fullerenes

are spherical molecules that are made of sixty carbon atoms. This type

of superconductors do not have the high critical temperatures that the

Type II superconductors do. Like ceramic superconductors, fullerenes

are a fairly recent discovery. They were accidentally discovered in

1985 by Robert F. Curl, Jr. and Richard E. Smalley of Rice University in

Houston and Professor Sir Harold W. Kroto of the University of Sussex in

Bighton, England. Because this material is fairly new, not much is

known about fullerides or why exactly they can superconduct. Fullernenes

are technically part of a larger family of organic conductors, which

include molecular salts, polymers, and pure carbon systems. The

molecular salts, often referred to as ?molecular? superconductors, are the

organic molecules that exhibit superconductive properties at very low

temperatures. Organic superconductors are composed of an electron donor

(the planar organic molecule) and an electron acceptor (a non-organic

anion). In 1993, Bob Cava, currently at Princeton University, and Bell

Labs discovered ?Borocarbides? which are one of the least-understood

superconductor systems of all. These superconductors raise questions about

the always-assumed theory that superconductors cannot be formed from

ferromagnetic transition metals – like iron, cobalt or nickel. With all

the questions that these superconductors arouse, atypical

superconductors are the most mysterious of all the other types.

The discovery of superconducting materials has opened the doors to

endless possibilities in technological advancements. Many transportation

vehicles such as trains are beginning to take advantage of

superconductors? magnetic-levitation ability. Using strong superconducting

magnets, these vehicles can be made to ?float? and virtually eliminate

friction between the train and its tracks. In biomagnetism, doctors can use

superconductors to save lives through the usage of impinging a strong

superconductor-derived magnetic field into the body and using a computer

to detect the energy released to view the inside of the human body.

This medical process is called Magnetic Resonance Imaging (MRI) and has

become crucial in determining what is wrong with the internal systems of

the body. Superconductors make s being able to accelerate sub-atomic

particles to nearly the speed of light, which is effective in

construction. Because of the little to no resistance of electric current in

superconductors, they have become extremely useful in electric generators

and other electrical devices. Superconducting wire has been found to be

more than ninety-nine percent more efficient than the typical copper

wires. ?Petaflop? computers being newly tested which uses

superconductors to have a thousand trillion floating operations per second, speeding

up the computer immensely. Superconductors have also been found to be

extremely effective in satellites and many military applications as

well. The list of possible uses of superconductors goes on and on, and

with the constant new discoveries and developments, the possibilities are

endless.

Through the discovery of superconductors, many technological

advancements were brought about. The science of superconductivity is relatively

new and much still remains unknown. The limits of superconductivity

have not yet been reached, and what theories that are in existence are

still under constant scrutiny. There are three main types of

superconductors that are widely used. From construction to transportation, from

electricity to computer, from military applications to the medical

field, superconductors have become immensely important in many aspects of

today?s world. Everyday, new things are discovered and a new technology

improved; this is just the beginning of superconductor?s abilities.

The possibilities are endless and the future looks bright for this

exciting material.