Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : doping

Structural Characterization of (Mg(1-x)pbxO)-NPs by Modified Pechini Method

Israa A. Najem; Fadhil Abd Rasin; Shaker J. Edrees

Engineering and Technology Journal, 2022, Volume 40, Issue 6, Pages 11-20
DOI: 10.30684/etj.v40i6.2147

The structural characterization was discussed in the present paper of the pure MgO nanoparticles and the doped (Mg(1-x)pbxO) nanoparticles specimens, where (0 ≤ x ≤ 0.03). The modified Pechini method was used to prepare all the specimens. From (DTA), the convenient temperature of decomposition from Mg(OH)2 to MgO was above 375°C. The structure investigation (XRD) revealed that all the specimens have identical space groups and index well to cubic structures. The obtained crystallite size by Scherrer''s equation was increased with increasing the fraction of doping except for (Mg0.97Pb0.03O) due to the formation of PbO oxide. The molecular vibration by FTIR demonstrated that all the pure and doped specimens have the same framework. As the incorporation of Pb2+ ions increases, the bands get broader, and the intensities increase in the ranging 800-400 cm-1 due to vibrations of O-Mg and O-Pb bands, respectively.

Anodic Inhibitor Doped Polypyrrole Coating to Reduce Corrosion in Petroleum Medium

R.A. Anaee; W.M. Salih; H.A. Abdullah

Engineering and Technology Journal, 2017, Volume 35, Issue 9, Pages 878-886
DOI: 10.30684/etj.35.9A.2

It is known that corrosion inhibitors and coatings are the best choices to use in oil refinery; therefore, we suggested using both inhibitors and coating to get more efficiency for corrosion control. Polypyrrole coating (PPy) without and with doping by anodic inhibitors were investigated to protect the tank from corrosion in light naphtha unit at Al-Dura refinery. Polypyrrole coating was deposited as nanofibers by electropolymerization using cyclic voltammetry method. Doped polypyrrole coating was applied by adding anodic inhibitor represented by chromate, phosphate and molybdate in acidic electrolyte. The coated layers were examined by SEM/EDS, FTIR and AFM. These examinations showed that coating layers were as nanofibers on carbon steel surface with average roughness in nanoscale as follow: 24.2 nm for PO4≡/PPy, 108 nm for PPy, 122 nm for B4O7=/PPy and 139 nm for MoO4=/PPy coating. Corrosion measurements were investigated by Potentiostat in oil medium at 60oC which represent the average temperature of light naphtha unit; the results showed that the highest protection efficiency was 78.34% in the presence of PO4≡/PPy coating and the others were 77.85% for PPy, 72.64% for B4O7=/PPy and 68.83% for MoO4=/PPy coating. The presence of inhibitor within the structure of polypyrrole coating leads to repairing the defects that may be produced by corrosion process and then the protection will take a long time to be destroyed. The protection by inhibitor doped PPy suggesting reduce the ionic conductivity of coating film especially in the presence of phosphate anions, where the porosity percents was 0.00025 for PO4≡/PPy compared with other coatings (0.04794 for PPy, 0.00043 for B4O7=/PPy, and 0.13083 for MoO4=/PPy).

Preparation and Characterization Study of Porous Silicon Doped with Cu and Ag

U. M. Nayef; A.M. Abdul Hussein; A. J. Kata

Engineering and Technology Journal, 2017, Volume 35, Issue 1B, Pages 8-12
DOI: 10.30684/etj.35.1B.2

In this paper, porous silicon was prepared by using electrochemical etching technique of p-type silicon acceptor, with a resistivity of, using hydrochloric acid with concentration of 24%. The etching current density effect 4, 12, 20mA/cm2 was carried out at constant etching time of 15min. The structural characteristics of the porous silicon and the doped porous silicon were studied and found an expansion in the spectrum of the X-rays and a simple shift in the diffraction angles while maintaining the surface direction (111). The morphological properties were studied using the atomic force microscope which showed pores formation and gives the pore diameter within the range of 19.08 to 44.73nm for the prepared samples. It was also noted that the rate of pore diameter and the thickness of the porous silicon layer increased with increasing etching current density. Electrical characteristics of the nanoscale porous silicon layer and the doped porous silicon with silver and copper showed that Current-Voltage (I-V) characteristics of the prepared samples to be a rectifying behavior. An improvement in the electrical characteristics of the doped porous silicon samples was observed

Study of Structural , Optical and Electrical Properties for Cr -Doped Tio2 Sensor for NH3 Gas

SelmaM.H.Al-Jawad; Zahraa Yassar Abbas

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 1137-1145

Titanium doxide (TiO2) thin films were deposited on quartz substrates by spray pyrolysis method using titanium tetrachloride as precursor solution. Thin films were deposited at temperature substrate 350 ◦C and annealed at 550 ◦C in air for 120 min. Polycrystalline thin films with anatas crystal structure, as evidenced from X-ray diffraction pattern. Optical study shows the optical band gap has been increased with increasing of dopant. Electrical properties have been studied by means of electrical resistivity and Hall measurement. The sensitivity of TiO2: 5% Cr to NH3 gas with concentration 5ppm at room temperature has been modified to (93) % as compared with a pure TiO2.

Raman Studies of Hg1-Xcuxba2ca2cu3o8 + ΔCompounds

Muna Moussa Abbass

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 258-263

Solid state reaction method by two steps was used to synthesize Hg1-xCuxBa2Ca2Cu3O8 + δ samples where x= 0.1and 0.5. Comparative Raman studies of Cu-doped Hg1-xCuxBa2Ca2Cu3O8 + δ were presented in an attempt to clarify the phononic modifications induced by Cu substitution. A number of phonon peaks showed up in the spectra assigned to different phases, usually small amounts of starting material that did not react or secondary products were unintentionally grown. On other hand foreign phases have much larger Raman signals and showed up strongly in the spectra.