Open AccessЧастотная зависимость угла диэлектрических потерь в неупорядоченных полупроводниках в терагерцовой области частот-=SUP=-*-=/SUP=-
Author(s) -
М.А. Ормонт,
И.П. Звягин
Publication year - 2018
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2018.05.45781.08d
Subject(s) - condensed matter physics , conductivity , relaxation (psychology) , thermal conduction , dielectric , zero (linguistics) , frequency dependence , range (aeronautics) , electrical resistivity and conductivity , physics , dielectric loss , nuclear magnetic resonance , mathematics , chemistry , materials science , thermodynamics , quantum mechanics , psychology , social psychology , linguistics , philosophy , composite material
Frequency dependence of the real part of the conductivity σ_1(ω) in the region of the transition from almost linear ( s < 1) to quadratic ( s ≈ 2) can indicate a change in the conduction mechanism (the transition from the variable-range to the fixed-range hopping with increasing frequency); in this case, the sharpness of the change in the slope of the frequency characteristic is related to the dependence of the preexponential factor of the resonance integral on the intercenter distance in the pair. The frequency dependence of the imaginary part of the conductivity σ_2(ω) has no kink in the vicinity of the transition frequency ωcr, remaining almost linear. A large dielectric loss angle |cotγ| = |σ_2|/σ_1 can indicate that the imaginary part of the conductivity at ω < ω_cr is defined by the larger zero-phonon contribution in σ_2^res the region of weak variation in the loss angle γ(ω), which significantly exceeds the relaxation contribution σ_2^res.