ATK was investigated to ascertain its IE(%) on ASTM A36 MS corrosion in a HCl medium. This was po... more ATK was investigated to ascertain its IE(%) on ASTM A36 MS corrosion in a HCl medium. This was possible through the use of WL, Td, Tm, PDP, EIS and SEM techniques. It was seen from all experimental results that, through adsorption onto the MS surface, ATK mitigated active corrosion sites. CR was seen to decrease with higher inhibitor Ct from 197.6 to 19.3 mg/hr-1 /cm 2. IE(%) of ATK, which rose from 50 to 90.2%, with corresponding increased Ct, from 150 to 750 ppm, was better by adding PPQ to it than ATS. An increase in Rct, up from 346 to 1153 Ω/cm 2 , and a decrease in icorr, from 312.2 to 64.4 mA, were seen, with higher Ct of ATK, which indicated reduced anodic dissolution and better CI. A mixed type inhibition was deduced from Tafel slopes of PDP results. A physical adsorption mechanism was proposed, while, in Td terms, ATK exhibited a stable and spontaneous reaction.
The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-... more The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Levaquin) on API 5L X-52 steel in 2 M HCl solution was investigated using potentiodynamic polarization method and quantum chemical study. Levaquin drug showed good inhibition efficiency of 88 and 95 % at 303 and 323 K, respectively. The results of experimental measurements revealed that Levaquin drug works as a mixed type inhibitor. Langmuir thermodynamic model was tested to describe the mode of inhibitor adsorption on the steel surface. The quantum chemical calculations confirmed the efficacy of Levaquin drug as a corrosion inhibitor.
Fruits are major sources of oils for human nutrition as well as for several industrial purposes. ... more Fruits are major sources of oils for human nutrition as well as for several industrial purposes. The properties of Dacryodes edulis fruit oils from two locations (Uyo and Ikom) were compared to those of Persea americana, a widely used oil in cosmeceutical formulations. All the oils extracted from each of these fruits were liquid at room temperature. The oil yield of P. americana (18.55%) was low in comparison to those of D. edulis-Uyo (49.57%) and D. edulis-Ikom (52.49%). The saponification value of D. edulis-Uyo, D. edulis-Ikom and P. americana oils were 189.33 mgKOH/g, 188.64 mgKOH/g and 185.13 mgKOH/g respectively, indicating their potential application in soap making. Fourier Transform Infrared (FT-IR) spectra of P. americana and D. edulis oils appear very similar, however, they revealed slight differences. Soap produced with D. edulis oil from Uyo gave the best quality soap considering the high fatty matter of 89.2% as compared to that of D. edulis soap from Ikom oil (65.4%) an...
Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution usi... more Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution using electrochemical impedance spectroscopy (EIS) and gravimetric techniques. The results obtained show an increase in inhibition efficiency and decrease in corrosion rate with increasing concentration of levofloxacin. The kinetic studies of the data followed a first order reaction. The adsorption of the inhibitor was found to be spontaneous and consistent with the assumption of Langmuir adsorption isotherm.
The inhibitive action of leaves (LV), seeds (SD) and a combination of leaves and seeds (LVSD) ext... more The inhibitive action of leaves (LV), seeds (SD) and a combination of leaves and seeds (LVSD) extracts of Phyllanthus amarus on mild steel corrosion in HCl and H 2 SO 4 solutions was studied using weight loss and gasometric techniques. The results indicate that the extracts functioned as a good inhibitor in both environments and inhibition efficiency increased with extracts concentration. Temperature studies revealed an increase in inhibition efficiency with rise in temperature and activation energies decreased in the presence of the extract. A mechanism of chemical adsorption of the plants components on the surface of the metal is proposed for the inhibition behaviour. The adsorption characteristics of the inhibitor were approximated by Temkin isotherm.
International Journal of Electrochemical Science, 2013
ABSTRACT The effects of ethanol (ENL), alkaloids (ANL) and non-alkaloids (NNL) extracts from the ... more ABSTRACT The effects of ethanol (ENL), alkaloids (ANL) and non-alkaloids (NNL) extracts from the root of Nauclea latifolia on the dissolution of carbon steel in H 2 SO 4 solutions were studied using gasometric techniques. The extracts showed significant inhibition of the rate of corrosion of the steel and the maximum inhibition efficiencies (η%) of the extracts followed the trend ANL>ENL>NNL. η% increased with the extracts concentration but decreased with temperature rise (NNL). The inhibitive action of the plant's extracts is attributed to the adsorption of mainly the alkaloids on the metal surface following Temkin adsorption isotherm.
The molecular beam epitaxy (MBE) growth of GaAs and InAs quantum dots on etched mesas has been st... more The molecular beam epitaxy (MBE) growth of GaAs and InAs quantum dots on etched mesas has been studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The [0 11]oriented mesas are etched into (1 0 0) GaAs substrates, exposing (5 3 3)B sidewall facets. At a substrate temperature of 610 1C a top (1 0 0) plane is seen to evolve on a ridge mesa structure. Alternatively, if the overgrowth is carried out at 630 1C no such facet is seen, and the top ridge remains unchanged during GaAs growth. By controlling the mesa shape, either ordered lines of dots can be grown or the dot density can be varied from o5 Â 10 8 cm À2 to 41 Â10 11 cm À2 on the same substrate in pre-defined regions. The dot distribution observed on the mesa sidewalls and top is discussed in terms of net migration of adatoms from different facets, underlying step density, step height and surface curvature of the mesa top.
The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated ... more The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated by potentiostatic polarisation measurements. The microstructure was evaluated using XRD and SEM. Cathodic hydrogen evolution, NDE, anodic dissolution of magnesium, the formation of magnesium hydride and possibly aluminium hydride were all restrained with Cd addition (AD62 alloy). The presence of Cd in AD62 alloy suppresses the micro-galvanic couple effect existing between and secondary phases in the alloy, and increases the polarisation resistance arising from the sum effect of the reduced current densities of all anodic and cathodic reactions.
The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-... more The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Levaquin) on API 5L X-52 steel in 2 M HCl solution was investigated using potentiodynamic polarization method and quantum chemical study. Levaquin drug showed good inhibition efficiency of 88 and 95 % at 303 and 323 K, respectively. The results of experimental measurements revealed that Levaquin drug works as a mixed type inhibitor. Langmuir thermodynamic model was tested to describe the mode of inhibitor adsorption on the steel surface. The quantum chemical calculations confirmed the efficacy of Levaquin drug as a corrosion inhibitor.
Fruits are major sources of oils for human nutrition as well as for several industrial purposes. ... more Fruits are major sources of oils for human nutrition as well as for several industrial purposes. The properties of Dacryodes edulis fruit oils from two locations (Uyo and Ikom) were compared to those of Persea americana, a widely used oil in cosmeceutical formulations. All the oils extracted from each of these fruits were liquid at room temperature. The oil yield of P. americana (18.55%) was low in comparison to those of D. edulis-Uyo (49.57%) and D. edulis-Ikom (52.49%). The saponification value of D. edulis-Uyo, D. edulis-Ikom and P. americana oils were 189.33 mgKOH/g, 188.64 mgKOH/g and 185.13 mgKOH/g respectively, indicating their potential application in soap making. Fourier Transform Infrared (FT-IR) spectra of P. americana and D. edulis oils appear very similar, however, they revealed slight differences. Soap produced with D. edulis oil from Uyo gave the best quality soap considering the high fatty matter of 89.2% as compared to that of D. edulis soap from Ikom oil (65.4%) an...
International Journal of Science and Research (IJSR)
Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution usi... more Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution using electrochemical impedance spectroscopy (EIS) and gravimetric techniques. The results obtained show an increase in inhibition efficiency and decrease in corrosion rate with increasing concentration of levofloxacin. The kinetic studies of the data followed a first order reaction. The adsorption of the inhibitor was found to be spontaneous and consistent with the assumption of Langmuir adsorption isotherm.
International Journal of Electrochemical Science, Dec 2, 2014
The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated ... more The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated by potentiostatic polarisation measurements. The microstructure was evaluated using XRD and SEM. Cathodic hydrogen evolution, NDE, anodic dissolution of magnesium, the formation of magnesium hydride and possibly aluminium hydride were all restrained with Cd addition (AD62 alloy). The presence of Cd in AD62 alloy suppresses the micro-galvanic couple effect existing between and secondary phases in the alloy, and increases the polarisation resistance arising from the sum effect of the reduced current densities of all anodic and cathodic reactions.
International Research Journal of Pure and Applied Chemistry
The corrosion inhibition potential of an antibiotic drug called moxifloxacin for API 5L X-52 stee... more The corrosion inhibition potential of an antibiotic drug called moxifloxacin for API 5L X-52 steel in 2 M HCl solution was investigated using experimental (gravimetric and electrochemical impedance spectroscopy) and theoretical approaches. Results obtained from gravimetric and electrochemical impedance spectroscopy measurements revealed that moxifloxacin inhibit the corrosion of steel, and recorded instantaneous maximum inhibition efficiency of 88% and 82.7% respectively at 303 ±1 K. Statistical consideration revealed that there was no significant difference between the two methods employed. The adsorption behavior of the inhibitor was best described by the Langmuir adsorption isotherm. Dipole moment calculated from quantum chemical calculation method was found to be in good agreement with those reported for some good corrosion inhibitors. The sites for nucleophilic and electrophilic attacks correspond to the atom N3,
International Journal of Electrochemical Science, May 1, 2012
Magnesium and its alloys are an excellent choice for lightweight structural applications in the a... more Magnesium and its alloys are an excellent choice for lightweight structural applications in the automotive and aerospace industry. These materials exhibit desirable characteristics of high specific strength, low density, excellent castability, damping ability, and ease in ...
The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated ... more The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated by potentiostatic polarisation measurements. The microstructure was evaluated using XRD and SEM. Cathodic hydrogen evolution, NDE, anodic dissolution of magnesium, the formation of magnesium hydride and possibly aluminium hydride were all restrained with Cd addition (AD62 alloy). The presence of Cd in AD62 alloy suppresses the micro-galvanic couple effect existing between and secondary phases in the alloy, and increases the polarisation resistance arising from the sum effect of the reduced current densities of all anodic and cathodic reactions.
The corrosion behaviour of AM60 magnesium alloy containing 1.88 wt.% Cd in 0.1 M NaCl solution wa... more The corrosion behaviour of AM60 magnesium alloy containing 1.88 wt.% Cd in 0.1 M NaCl solution was investigated by weight loss and hydrogen evolution measurements. The microstructure was evaluated using EPMA. Cd was observed to have an even distribution, hence, no new phase was formed. The corrosion resistance was enhanced by the addition of Cd. The rate of corrosion reduced by a factor of 1.5 times that of AM60 alloy. The microstructure played a crucial role as the presence of defects in the alloys initiated and accelerated corrosion.
The fabrication of a cross-wire p-in light emitting diode (LED) by molecular beam epitaxial overg... more The fabrication of a cross-wire p-in light emitting diode (LED) by molecular beam epitaxial overgrowth on mesa-patterned GaAs(100) substrates is presented. Micron-wide mesa stripes fabricated by standard photolithography are subsequently narrowed to sub-micron dimensions by GaAs overgrowth due to net migration towards the mesa top. Chains of InAs quantum dots (QDs) can then be grown in a self-aligned manner on top of the narrow GaAs ridge mesa, forming the active region of the QD-chain LED. The kinetics of the overgrowth is discussed and the electroluminescence operation of the LED is presented.
ATK was investigated to ascertain its IE(%) on ASTM A36 MS corrosion in a HCl medium. This was po... more ATK was investigated to ascertain its IE(%) on ASTM A36 MS corrosion in a HCl medium. This was possible through the use of WL, Td, Tm, PDP, EIS and SEM techniques. It was seen from all experimental results that, through adsorption onto the MS surface, ATK mitigated active corrosion sites. CR was seen to decrease with higher inhibitor Ct from 197.6 to 19.3 mg/hr-1 /cm 2. IE(%) of ATK, which rose from 50 to 90.2%, with corresponding increased Ct, from 150 to 750 ppm, was better by adding PPQ to it than ATS. An increase in Rct, up from 346 to 1153 Ω/cm 2 , and a decrease in icorr, from 312.2 to 64.4 mA, were seen, with higher Ct of ATK, which indicated reduced anodic dissolution and better CI. A mixed type inhibition was deduced from Tafel slopes of PDP results. A physical adsorption mechanism was proposed, while, in Td terms, ATK exhibited a stable and spontaneous reaction.
The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-... more The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Levaquin) on API 5L X-52 steel in 2 M HCl solution was investigated using potentiodynamic polarization method and quantum chemical study. Levaquin drug showed good inhibition efficiency of 88 and 95 % at 303 and 323 K, respectively. The results of experimental measurements revealed that Levaquin drug works as a mixed type inhibitor. Langmuir thermodynamic model was tested to describe the mode of inhibitor adsorption on the steel surface. The quantum chemical calculations confirmed the efficacy of Levaquin drug as a corrosion inhibitor.
Fruits are major sources of oils for human nutrition as well as for several industrial purposes. ... more Fruits are major sources of oils for human nutrition as well as for several industrial purposes. The properties of Dacryodes edulis fruit oils from two locations (Uyo and Ikom) were compared to those of Persea americana, a widely used oil in cosmeceutical formulations. All the oils extracted from each of these fruits were liquid at room temperature. The oil yield of P. americana (18.55%) was low in comparison to those of D. edulis-Uyo (49.57%) and D. edulis-Ikom (52.49%). The saponification value of D. edulis-Uyo, D. edulis-Ikom and P. americana oils were 189.33 mgKOH/g, 188.64 mgKOH/g and 185.13 mgKOH/g respectively, indicating their potential application in soap making. Fourier Transform Infrared (FT-IR) spectra of P. americana and D. edulis oils appear very similar, however, they revealed slight differences. Soap produced with D. edulis oil from Uyo gave the best quality soap considering the high fatty matter of 89.2% as compared to that of D. edulis soap from Ikom oil (65.4%) an...
Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution usi... more Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution using electrochemical impedance spectroscopy (EIS) and gravimetric techniques. The results obtained show an increase in inhibition efficiency and decrease in corrosion rate with increasing concentration of levofloxacin. The kinetic studies of the data followed a first order reaction. The adsorption of the inhibitor was found to be spontaneous and consistent with the assumption of Langmuir adsorption isotherm.
The inhibitive action of leaves (LV), seeds (SD) and a combination of leaves and seeds (LVSD) ext... more The inhibitive action of leaves (LV), seeds (SD) and a combination of leaves and seeds (LVSD) extracts of Phyllanthus amarus on mild steel corrosion in HCl and H 2 SO 4 solutions was studied using weight loss and gasometric techniques. The results indicate that the extracts functioned as a good inhibitor in both environments and inhibition efficiency increased with extracts concentration. Temperature studies revealed an increase in inhibition efficiency with rise in temperature and activation energies decreased in the presence of the extract. A mechanism of chemical adsorption of the plants components on the surface of the metal is proposed for the inhibition behaviour. The adsorption characteristics of the inhibitor were approximated by Temkin isotherm.
International Journal of Electrochemical Science, 2013
ABSTRACT The effects of ethanol (ENL), alkaloids (ANL) and non-alkaloids (NNL) extracts from the ... more ABSTRACT The effects of ethanol (ENL), alkaloids (ANL) and non-alkaloids (NNL) extracts from the root of Nauclea latifolia on the dissolution of carbon steel in H 2 SO 4 solutions were studied using gasometric techniques. The extracts showed significant inhibition of the rate of corrosion of the steel and the maximum inhibition efficiencies (η%) of the extracts followed the trend ANL>ENL>NNL. η% increased with the extracts concentration but decreased with temperature rise (NNL). The inhibitive action of the plant's extracts is attributed to the adsorption of mainly the alkaloids on the metal surface following Temkin adsorption isotherm.
The molecular beam epitaxy (MBE) growth of GaAs and InAs quantum dots on etched mesas has been st... more The molecular beam epitaxy (MBE) growth of GaAs and InAs quantum dots on etched mesas has been studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The [0 11]oriented mesas are etched into (1 0 0) GaAs substrates, exposing (5 3 3)B sidewall facets. At a substrate temperature of 610 1C a top (1 0 0) plane is seen to evolve on a ridge mesa structure. Alternatively, if the overgrowth is carried out at 630 1C no such facet is seen, and the top ridge remains unchanged during GaAs growth. By controlling the mesa shape, either ordered lines of dots can be grown or the dot density can be varied from o5 Â 10 8 cm À2 to 41 Â10 11 cm À2 on the same substrate in pre-defined regions. The dot distribution observed on the mesa sidewalls and top is discussed in terms of net migration of adatoms from different facets, underlying step density, step height and surface curvature of the mesa top.
The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated ... more The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated by potentiostatic polarisation measurements. The microstructure was evaluated using XRD and SEM. Cathodic hydrogen evolution, NDE, anodic dissolution of magnesium, the formation of magnesium hydride and possibly aluminium hydride were all restrained with Cd addition (AD62 alloy). The presence of Cd in AD62 alloy suppresses the micro-galvanic couple effect existing between and secondary phases in the alloy, and increases the polarisation resistance arising from the sum effect of the reduced current densities of all anodic and cathodic reactions.
The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-... more The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Levaquin) on API 5L X-52 steel in 2 M HCl solution was investigated using potentiodynamic polarization method and quantum chemical study. Levaquin drug showed good inhibition efficiency of 88 and 95 % at 303 and 323 K, respectively. The results of experimental measurements revealed that Levaquin drug works as a mixed type inhibitor. Langmuir thermodynamic model was tested to describe the mode of inhibitor adsorption on the steel surface. The quantum chemical calculations confirmed the efficacy of Levaquin drug as a corrosion inhibitor.
Fruits are major sources of oils for human nutrition as well as for several industrial purposes. ... more Fruits are major sources of oils for human nutrition as well as for several industrial purposes. The properties of Dacryodes edulis fruit oils from two locations (Uyo and Ikom) were compared to those of Persea americana, a widely used oil in cosmeceutical formulations. All the oils extracted from each of these fruits were liquid at room temperature. The oil yield of P. americana (18.55%) was low in comparison to those of D. edulis-Uyo (49.57%) and D. edulis-Ikom (52.49%). The saponification value of D. edulis-Uyo, D. edulis-Ikom and P. americana oils were 189.33 mgKOH/g, 188.64 mgKOH/g and 185.13 mgKOH/g respectively, indicating their potential application in soap making. Fourier Transform Infrared (FT-IR) spectra of P. americana and D. edulis oils appear very similar, however, they revealed slight differences. Soap produced with D. edulis oil from Uyo gave the best quality soap considering the high fatty matter of 89.2% as compared to that of D. edulis soap from Ikom oil (65.4%) an...
International Journal of Science and Research (IJSR)
Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution usi... more Levofloxacin has been tested as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution using electrochemical impedance spectroscopy (EIS) and gravimetric techniques. The results obtained show an increase in inhibition efficiency and decrease in corrosion rate with increasing concentration of levofloxacin. The kinetic studies of the data followed a first order reaction. The adsorption of the inhibitor was found to be spontaneous and consistent with the assumption of Langmuir adsorption isotherm.
International Journal of Electrochemical Science, Dec 2, 2014
The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated ... more The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated by potentiostatic polarisation measurements. The microstructure was evaluated using XRD and SEM. Cathodic hydrogen evolution, NDE, anodic dissolution of magnesium, the formation of magnesium hydride and possibly aluminium hydride were all restrained with Cd addition (AD62 alloy). The presence of Cd in AD62 alloy suppresses the micro-galvanic couple effect existing between and secondary phases in the alloy, and increases the polarisation resistance arising from the sum effect of the reduced current densities of all anodic and cathodic reactions.
International Research Journal of Pure and Applied Chemistry
The corrosion inhibition potential of an antibiotic drug called moxifloxacin for API 5L X-52 stee... more The corrosion inhibition potential of an antibiotic drug called moxifloxacin for API 5L X-52 steel in 2 M HCl solution was investigated using experimental (gravimetric and electrochemical impedance spectroscopy) and theoretical approaches. Results obtained from gravimetric and electrochemical impedance spectroscopy measurements revealed that moxifloxacin inhibit the corrosion of steel, and recorded instantaneous maximum inhibition efficiency of 88% and 82.7% respectively at 303 ±1 K. Statistical consideration revealed that there was no significant difference between the two methods employed. The adsorption behavior of the inhibitor was best described by the Langmuir adsorption isotherm. Dipole moment calculated from quantum chemical calculation method was found to be in good agreement with those reported for some good corrosion inhibitors. The sites for nucleophilic and electrophilic attacks correspond to the atom N3,
International Journal of Electrochemical Science, May 1, 2012
Magnesium and its alloys are an excellent choice for lightweight structural applications in the a... more Magnesium and its alloys are an excellent choice for lightweight structural applications in the automotive and aerospace industry. These materials exhibit desirable characteristics of high specific strength, low density, excellent castability, damping ability, and ease in ...
The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated ... more The corrosion behaviour of AM60 and AD62 magnesium alloy in 0.1 M NaCl solution was investigated by potentiostatic polarisation measurements. The microstructure was evaluated using XRD and SEM. Cathodic hydrogen evolution, NDE, anodic dissolution of magnesium, the formation of magnesium hydride and possibly aluminium hydride were all restrained with Cd addition (AD62 alloy). The presence of Cd in AD62 alloy suppresses the micro-galvanic couple effect existing between and secondary phases in the alloy, and increases the polarisation resistance arising from the sum effect of the reduced current densities of all anodic and cathodic reactions.
The corrosion behaviour of AM60 magnesium alloy containing 1.88 wt.% Cd in 0.1 M NaCl solution wa... more The corrosion behaviour of AM60 magnesium alloy containing 1.88 wt.% Cd in 0.1 M NaCl solution was investigated by weight loss and hydrogen evolution measurements. The microstructure was evaluated using EPMA. Cd was observed to have an even distribution, hence, no new phase was formed. The corrosion resistance was enhanced by the addition of Cd. The rate of corrosion reduced by a factor of 1.5 times that of AM60 alloy. The microstructure played a crucial role as the presence of defects in the alloys initiated and accelerated corrosion.
The fabrication of a cross-wire p-in light emitting diode (LED) by molecular beam epitaxial overg... more The fabrication of a cross-wire p-in light emitting diode (LED) by molecular beam epitaxial overgrowth on mesa-patterned GaAs(100) substrates is presented. Micron-wide mesa stripes fabricated by standard photolithography are subsequently narrowed to sub-micron dimensions by GaAs overgrowth due to net migration towards the mesa top. Chains of InAs quantum dots (QDs) can then be grown in a self-aligned manner on top of the narrow GaAs ridge mesa, forming the active region of the QD-chain LED. The kinetics of the overgrowth is discussed and the electroluminescence operation of the LED is presented.
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Papers by Magdalene Ikpi