Thermal, Structural, AC Conductivity, and Dielectric Properties of Ethyl-2-amino-6-ethyl-5-oxo-4-(3-phenoxyphenyl)-5,6- dihydro-4H-pyrano[3,2-c]quinoline-3-carboxylate Thin Films

Thermal, structural, alternating-current (AC) conductivity (rAC), and dielec-
tric properties of ethyl-2-amino-6-ethyl-5-oxo-4-(3-phenoxyphenyl)-5,6-dihy-
dro-4H-pyrano[3,2-c]quinoline-3-carboxylate (HPQC) thin films have been
studied. Thermogravimetry analysis and differential scanning calorimetry
confirmed the thermal stability of HPQC over a wide temperature range.
Fourier-transform infrared spectroscopy and x-ray diffraction analysis were
carried out on HPQC in powder form and as-deposited thin film. The crystal
system and space group type were determined for HPQC in powder form. The
AC conductivity and dielectric properties were determined in the frequency
range from 0.5 kHz to 5 MHz and temperature range from 296 K to 443 K.
The AC electrical conduction of HPQC thin film was found to be governed by
the small-polaron tunneling mechanism. The polaron hopping energy (WH),
tunneling distance (R), and density of states (N) near the Fermi level were
determined as functions of temperature and frequency. The dielectric prop-
erties of HPQC thin film were studied by analysis of Nyquist diagrams, the
dissipation factor (tan d), and real (e¢) and imaginary (e¢¢) parts of the dielectric
constant.