title: Spectral-optical-electrical-thermal properties of deposited thin films of nano-sized calcium(II)-8-hydroxy-5,7-dinitroquinolate complex.
abstract: Spectral-optical-electrical-thermal properties of deposited thin films of nano-sized calcium(II)-8-hydroxy-5,7-dinitroquinolate complex, Ca[((NO(2))(2)-8HQ)(2)], were explored, studied and evaluated in this work. Thin films of Ca[((NO(2))(2)-8HQ)(2)] were assembled by using a direct, simple and efficient layer-by-layer (LBL) chemical deposition technique. The optical properties of thin films were investigated by using spectrophotometric measurements of transmittance and reflectance at normal incidence in the wavelength range 200-2500 nm. The refractive index, n, and the absorption index, k, of Ca[((NO(2))(2)-8HQ)(2)] films were determined from the measured transmittance and reflectance. The real and imaginary dielectric constants were also determined. The analysis of the spectral behavior of the absorption coefficient in the intrinsic absorption region reveals a direct allowed transition with band gaps of 1.1 eV and 2.4 eV for the optical and transport energy gaps, respectively. The current-voltage characteristics of Ca[((NO(2))(2)-8HQ)(2)] showed a trap-charge limited conduction in determining the current at the intermediate and high bias regimes. Graphical representation of the current-voltage characteristics yields three distinct linear parts indicating the existence of three conduction mechanisms. Structural characterization and identification were confirmed by using Fourier transform infrared spectroscopy (FT-IR). Scanning electron microscopy (SEM) was also used to image the surface morphology of the deposited nano-sized metal complex and such study revealed a high homogeneity in surface spherical particle distribution with average particles size in the range 20-40 nm. Thermal gravimetric analysis (TGA) was also studied for [(NO(2))(2)-8HQ] and Ca[((NO(2))(2)-8HQ)(2)] to evaluate and confirm the thermal stability characteristics incorporated into the synthesized nano-sized Ca[((NO(2))(2)-8HQ)(2)] complex.
authors.affiliation: Thin Film Laboratory, Physics Department, Faculty of Education, Ain Shams University, Heliopolis, Roxy, Cairo 11757, Egypt.
authors.forename: A A M
authors.initials: AA
authors.lastname: Farag
authors.forename: Sawsan M S
authors.initials: SM
authors.lastname: Haggag
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Mahmoud
mesh_terms: D002118:Calcium / Q000737:chemistry*; D003460:Crystallization; D004581:Electronics; D006358:Hot Temperature; D008024:Ligands; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008956:Models, Chemical; D015233:Models, Statistical; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics / Q000379:methods; D009991:Oscillometry; D011804:Quinolines / Q000737:chemistry*; D012031:Refractometry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013818:Thermogravimetry / Q000379:methods
chemical_list: D008024:Ligands; D011804:Quinolines; C569489:calcium(II)-8-hydroxy-5,7-dinitroquinolate; D002118:Calcium