Kuis 1 solid state physics pusing pala kau, Exercises of Physics

Download Kuis 1 solid state physics pusing pala kau and more Exercises Physics in PDF only on Docsity!

1. Copper has a mass density p = 8.95 g/cm’, and electrical resistivity 1.55x10° ohm-m at room temperature. Assuming that the effective mass of electron in Cu m* = mo, (170 — free electron mass) calculate: a) The concentration of the conduction electrons b) The mean relaxation time t c) The Fermi energy Zr and the Fermi velocity vr d) The mean free path at the Fermi level /r 2. The He? atom has spin % and is a fermion. The density of liquid He’ is 0.081 g/cm? near absolute zero. Calculate the Fermi energy Z; and the Fermi temperature 7. 3. Estimate the fraction of electrons excited above the Fermi level at room temperature for Cu and Na. The electron effective masses in Cu and Na are 1.0x/mo and 1.2 mo, respectively. where imo — free electron mass. 4. At what temperature Tp does the specific heat of the free electrons become larger than the specific heat of the lattice? Express Jp in terms of the Debye temperature and the electron concentration. Calculate To for copper. (The Debye temperature is 343 K).