The Frenkel effect was studied in EuLaGa3S7 single crystals with a res
istivity of 10(9)-10(13) Omega cm and band gap E-g = 3.0 eV. Dielectri
c constant epsilon = 8, electron free path lambda = 6 x 10(-6) cm, and
trap concentration N-t = 1.2 x 10(15) cm(-3) were determined from the
I-V characteristics of In-EuLaGa3S7-In structures recorded in electri
c fields up to 10(4) V/cm in the temperature range from 300 to 360 K.