ISSN:
1573-0689
Keywords:
Indolemelanin
;
pirocatechol
;
a.c. and d.c. conductivity
;
dielectric permittivity
;
loss angle tg
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Physics
Notes:
Abstract Detailed studies on dielectric and electric properties of synthetic pirocatechol and indolederived melanin, pure and doped with Eu3+, have been performed, D.C. and a.c. electrical conductivity as well as dielectric permittivity and loss angle tg have been investigated. Activation energy of d.c. conductivity for the investigated temperature range (0°C〈T〈50°C equals 0.63 eV for pirocatechol and 0.62 eV for indolemelanin. Europium ions Eu3+ doped to the samples do not influence the values of activation energy, but the addition of Eu3+ ions decreases the conductivity values. On the basis of depolarization current curves the energy of trap level referred to Eu3+ has been calculated. It equals 0.58 eV for pirocatechol and 0.60 eV for indolemelanin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00701009
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