Hey people..

 

Almost everyone has heard of the phenomenon called Superconductivity..

It has taken the world by storm and is the foundation of  thousands of ideas that can hardly be imagined without  superconductivity..

 

However Superconduction has been possible only at extremely low temperatures that restricts the use of superconductors in day to day life at room temperature..

 

Maybe one day we will be able to manufacture supercondutors that work even at room temperature..till then we have to wait as the highest temperature at which superconduction is possible is perhaps 150 K achieved by scientists from superconductors.org

 

There are many types of superconducting materials..chief among them are the Metallic and Ceramic Superconductors

 

Superconduction in metallic superconductors is quite easy to understand..as we will see now..

 

 

What is superconductivity and why it happens?

Let us see how this happens in METALLIC superconductors

 

 

In a metallic crystal, there exists a number of definitely arranged metallic ions surrounded by a sea of electrons

At room temperature, the lattice of these ions is constantly vibrating as a result of favourable thermal energy

Now when a voltage is applied to this crystal, the electrons start flowing in the conductor

Now as these electrons traverse through the crystal, they collide with the ions and part of their energy is lost in the form of heat.

This restricts the number of electrons flowing at a time and thus reduces current[the flow of electrons] greatly. This is also what we call "resistance".

Now, we can easily imagine that higher the tempearture, faster is the vibrational motion of electrons and higher the probability of collisions.

 

Hence, lower the temperature, lower the number of collisions

Now at a certain temperature, the vibrations become so less that the electrons can pass through virtually without hindrance.

 

This is called the critical temperature, the temperature at which the phenomenon of superconductivity begins to reveal itself.

 

Now since the positively charged ions are in a virtually stationary state, they are attracted towards the electrons as they pass by them through the cavities and a tunnel like cavity is formed, outlined by positive ions. However, they can shift very little as the lattice holds them in place

 

As a result of this minute movement, the concentration of positive charge in that region rises considerably and the electrons of the nearby region are attracted towards the opening and an undidturbed current begins to flow, consisting of  steady stream of electrons that follow a trail of positive charge. This is called superconduction.

 

We can easily see that superconduction is distinct from the ideal concept of free conduction in classical physics as it emphasises on the undisturbed flow of a few electrons that are in the vicinity of the region with high positive charge density instead of zero collisions.

 

 

We can visualise superconduction through this simple analogy

 

Consider a rope bridge on a river. When someone walks over it, it shakes violently making it very difficult for the person crossing it to walk steadily.

Now if the person is in a hurry [as most electrons are] it will be even more difficult for him to cross the bridge, and he will falter many times.

 

 

Now imagine that you reach the bridge someday. Determined to make the world a better place to live in, you build wooden support for the bridge. As a result, the structure becomes far more stable and it becomes very easy for people to cross it.

 

 

Now if there are four such rope bridges on the river, people who want to cross the river will automatically be drawn to the stronger bridge as it is easier to cross.

 

 

When the use of this birdge increases its wear and tear increases and someday, it will eventually fall and many people will have to change their course.

 

 

 

I hope this article has helped you to understand superconductivity.

The cause of superconductivity is a hotly debated topic and quite obscure.

If I have not been able to provide proper information, kindly tell me about it, so that even my misconceptions are cleared.

 

This article is an original and has been made possible after I referred the website www.superconductors.org

Kindly visit the same for further information on superconductors.

 

Cheers !