A Study Into Energy Gap in Super Conductor
CHAPTER ONE
OBJECTIVES OF THE STUDY
The primary objective of the study is to examine the energy gap in superconductors. Specific objectives of the study are:
- To critically examine the various types and properties of super conductors
- To examine energy gaps in low temperature super conductors.
- To examine energy gaps in high temperature super conductors.
CHAPTER TWO
LITERATURE REVIEW
SUPERCONDUCTOR
A superconductor is a material that can conduct electricity or transport election form one atom to another with no resistance. This means no heat, sound or any other form of energy would be released from the material when it has reached “critical temperature” (Tc) becomes superconductive. Unfortunately, most materials must be in an extremely low energy state (very cold) in order to become superconductive currently an excessive amount of energy must be used in the cooling process making superconductors inefficient and uneconomical.
TYPES OF SUPERCONDUCTORS
There are two types of superconductors, namely
TYPE 1 Superconductors and
TYPE 2 Superconductors
Type 1 superconductor and a periodic chat comparison.
The type 1 superconductor is mainly comprises of metal and metalloids that shows some conductivity at room temperature. They require incredibly cold temperature to slow down molecular vibration sufficiently to facilitate unimpeded electron flow in accordance with what is know as BCS theory (Bardeen et al 1957).
Types I super conductors characterized as the “SOFT” superconductors where discovered first superconductive. They exhibited a very sharp transition to a superconductive state (see diagram/graph above) and perfect diamagnetism the ability to repel a magnetic field.
Below is the table of some type I superconductor their TC’s and lattices structure of each.
CHAPTER THREE
CALCULATIONS AND METHODS
CALCULATION OF ENERGY GAP IN LOW TEMPERATURE SUPERCONDUCTORS (LTS) AND HIGH TEMPERATURE SUPERCONDUCTORS (HTS)
There is a widely accepted temperature that separate low temperature superconductors from high temperature superconductors. However, all superconductors know before the discovery of superconductor oxocuprate would be classified as “low temperature superconductors (LTS) the lanthanum based cuprate with critical temp. (TC) of about 35k is generally considered to be the first high temperature superconductor.
Certainly, any compound that would superconductor above the boiling point of liquid nitrogen of 77k would be termed a high temperature superconductor (HTS)
CHAPTER FOUR
CONCLUSION
GENERAL CLASSIFICATION OF SUPER CONDUCTORS.
There is not just one criterion to classify super conductors. The most common are:
(a) By their physical properties
They can be type 1 (if their phase transition is of first order) or type II (if their phase transition is of second order)
(b) By the theory to explain them
They can be conventional (if they are fully explained with the BCS theory or related theories) or unconventional (if no).
(c) By their critical temperature (TC):
They can be high temperature (HTS) i.e generally considered if they reach the superconducting state just by cooling them with liquid nitrogen (if Tc > 77K) or low temperature (LTS) i.e if they need other technique to be cooled under their critical temperature (if Tc < 77K) or >.
- By materials: If they can be chemical element (such as mecury or lead), alloys (as niobium-titanium or germanium-niobium) ceramics (as YBCO or the magnesium diboride), or organic superconductors (as fullerenes or carbon nonotubes, which technically might be included between the chemical element as they are made of carbon).
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