Plasmon Damping in Be, Mg, Al, Si, Ge and Sn

Characters of the plasma loss of electrons-plasmon energy, dispersion coefficient and angular dependences of both the half-width and the intensity of the loss peak-were measured for Be, Mg, Al, Si, Ge and Sn at 40 kV. The angular dependence of the half-width was analyzed in the form of Γ p = A + B θ 2 . As the result, it was found that there were two groups: Al, Mg and Sn belonged to the first group in which A had relatively small values and B was positive, and Ge, Si and Be belonged to the second group in which A had relatively large values and B was negative. The electron-electron interaction would be an important factor of the plasmon damping for the second group. The angular dependence of the intensity agreed with θ -2 law for the first group but did not for the second group. An anomalous damping was not observed in amorphous Ge and Si.