| 20.6 |
Problems |
| 20.1) |
One million Na atoms are placed on a straight line. If the energy of the highest level of the 3s band is 1 ev higher than the lowest energy level of the band and if all the levels in the band are equally spaced, what is the energy difference between adjacent levels? Is the thermal energy (kT = 207 cm-1 at room temperature ) sufficient to excite electrons among these levels ? If the number of atoms is increased to 6 * 1023, what is the difference in energy between adjacent energy levels? if you treat this as a particle in a box problem, what will be the length of a one-dimensional box whose energy for the n = 1 state corresponds to the above energy difference? |
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| 20.2) |
The distribution of electrons in the energy levels in the electronic bands follows the Fermi-Dirac distributions. Instead of electrons which are Fermions (particles with half integral spins), if we were to fill these levels with bosons (particles with integral spins, e.g., photons, nuclei of nitrogen atoms) what are the major differences that you would expect? |
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| 20.3) |
From literature or some common websites, list the name of a few commonly used superconductors in daily life. Also find out the temperature below which they become superconducting, their cost per gram of substance, their structures, name of the inventor and the year of invention and the nature of their specific application. |
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