A Study Into Energy Gap In Super Conductors

Project and Seminar Material for Physics

Abstract

The study of super conductors, its concept and the various theories are still a mystery in the field of Solid-State Physics. Although a few theories try to explain the working principle (i.e. how and why it works) of super-conductors scientists believed that a full acknowledgment of its energy gap; is dependence on temperature and pressure and the effect of doping may finally unlock the door to a vast acknowledge of superconductivity. This project work brings all in one piece, the various principle and theories as derived by some renowned scientist working to ensure full understanding in this area of physics. It is believed that High Temperature Superconductors (HTS) i.e. superconductors with considerable high critical temperature hold the key to the practical application of super conductors.

Chapter One

1.1 Introduction

Super conductivity is a fascinating and challenging field of physics. Scientists and Engineers throughout the world have been striving to develop it for many years. For nearly 75 years superconductivity has been a relatively obscure subject. Until recently, because of the cryogenic requirement of low temperature superconductors, superconductivity at the high school level was merely an interesting topic occasionally discussed in a Physics class. Today however, superconductivity is being applied to many diverse areas such as: medicine, theoretical and experimental science, the military, transportation, power production, electronics, as well as many other areas. With the discovery of high temperature superconductor which can operate at liquid nitrogen temperature (77k), superconductivity is now well known within the reach of high school student. Unique and exciting opportunities now exist today for our student to explore and experiment with this new and important technological field of Physics. Major advances in low-temperature refrigerator were made during the late 19th century. (Bedornz, J and Muller, K; 1986).

1.2 Problem Statement

It is not practical to transmit electric energy if you need liquid helium temperatures. The cooling costs are prohibitive. The current state of the art are cables using thin films of BSCCO. They can operate at 77 K without problems. The current world record for such a cable in a vacuum tube is several kilometers but after some distance you need a small building along the cable to cool the liquid nitrogen inside the cable again.