Electrical transport as a function of temperature in urea and cobalt (III)-urea complex

Citation
Mm. Sallam et al., Electrical transport as a function of temperature in urea and cobalt (III)-urea complex, J MAT S-M E, 10(7), 1999, pp. 479-482
Citations number
20
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
ISSN journal
09574522 → ACNP
Volume
10
Issue
7
Year of publication
1999
Pages
479 - 482
Database
ISI
SICI code
0957-4522(199909)10:7<479:ETAAFO>2.0.ZU;2-V
Abstract
The temperature dependence of the electrical conductivity, and the voltage- current dependence of urea and its cobalt solid complex were determined. Th e values of the thermal activation energies indicate that the two compounds behave like semiconductors. The semiconducting properties of the ligand 'u rea' are due to the electron delocalization via pi-bond formation (C=NH, C= (+)(2)) as well as the lone pair of electrons on the oxygen atoms of urea m olecules. The high conductivity values of urea compared with those of its c obalt solid complex was suggested to be due to the ease of releasing the lo ne pair electrons on the oxygen atom as well as the hydrogen transfer durin g enol formation of urea molecules. The infrared, ultraviolet and visible a bsorption measurements were carried out to rationalize the mechanism of the conduction process in the investigated compounds.