Silicon nanoparticles with diameters ranging from 3 to 50 nm were prepared by thermal evaporation... more Silicon nanoparticles with diameters ranging from 3 to 50 nm were prepared by thermal evaporation. The nanoparticles showed visible light emissions from 5000 A to 9000 A, with peak intensity at 8000-8200 A, when excited with a He-Cd laser. The intensity increased with decreasing particle size. Based on the photoluminescence (PL) characteristics, it is suggested that the PL for particles larger than 9 nm is surface state-induced, while the PL for those smaller than 9 nm is ascribed to quantum confinement effects.
An electrochemical technique was used to study the effects of elastic stress on hydrogen permeati... more An electrochemical technique was used to study the effects of elastic stress on hydrogen permeation in AL 2% 4-2 ferritic stainless steel. Tensile stress increased the permeability. The change in diffusivity induced by the stress was relatively inconsistent, but the activation energy consistently increased. The average partial molar volume of hydrogen deduced from the increased hydrogen flux at 40-60 "C was 2.3 cm3 mol-'.
TiO2 multi-walled nanotube arrays (MWNTAs) were synthesized by atomic layer deposition (ALD) usin... more TiO2 multi-walled nanotube arrays (MWNTAs) were synthesized by atomic layer deposition (ALD) using anodic aluminum oxide (AAO) as the template. TiO2 and Al2O3 layers were alternately deposited into the AAO pores by ALD. The tube thickness and the gap span were controlled by the ALD cycle numbers of TiO2 and Al2O3, respectively. A MWNT composed of two or three concentric tubes with different diameters was formed after removal of Al2O3. Silver nanoparticles were then deposited on both inner and outer surfaces of the tubes by photochemical reduction. Degradation of methylene blue was carried out to evaluate the photocatalytic activity of bare and silver-loaded TiO2 MWNTAs. It was found that the amount of TiO2, the reaction surface area, the crystalline phase, and silver modification were the factors to determine the photocatalytic activity. The triple-walled MWNTAs showed the best performance, and Ag loading further enhanced the activity.
Atomic layer deposition (ALD) has been widely used to prepare high-k dielectric films for metalo... more Atomic layer deposition (ALD) has been widely used to prepare high-k dielectric films for metaloxidesemiconductor field-effect transistors and the capacitor layer of dynamic random-access memory.1 The self-limiting gassolid reaction of ALD processes enables ...
... [6] ON Senkov and FH Froes, Int. J. Hydrogen Energy 24 (1999), p. 565. Article | PDF (390 K) ... more ... [6] ON Senkov and FH Froes, Int. J. Hydrogen Energy 24 (1999), p. 565. Article | PDF (390 K) | View Record in Scopus | Cited By in Scopus (113). [7] D. Eliezer, N. Eliaz, ON Senkov and FH Froes, Mater. Sci. Eng. A 280 (2000), p. 220. Article | PDF (101 K) |.
Carbon nanotubes have been synthesized by a LPCVD on nanocrystalline Fe-Pd film. CNTs are grown f... more Carbon nanotubes have been synthesized by a LPCVD on nanocrystalline Fe-Pd film. CNTs are grown for 30 min and 1 h respectively. From the SEM images, the diameter of these nanotubes varies from 40-80 nm and the length is several micro-meter approximately. TEM observations suggest that the CNTs are multi-walled and the structure changes from ordinary geometry of CNTs to bamboo shaped. We have observed sharp G and D bands in the Raman spectra of these carbon nanotubes. Higher D-band is observed for the carbon nanotubes grown for longer time (1 h), showing that these nanotubes contain more amorphous carbon. The field emission measurements for these CNTs are also performed. For CNTs grown for longer time (1 h), a superior turn-on field of 4:88 V=mm (when the current density achieves 10 mA=cm 2) is obtained and a current density of 29:36 mA=cm 2 can be generated at 9:59 V=mm.
Cracking in amorphous ribbon of Fe40Ni38Mo4B18 without external loading could be induced by catho... more Cracking in amorphous ribbon of Fe40Ni38Mo4B18 without external loading could be induced by cathodic charging with hydrogen in 0.1 N H2SO4 + 5 mg/L NaAsO2. However, before cracking was initiated, the effect of hydrogen on the mechanical properties could be eliminated if hydrogen had been removed. A series of static charging experiments was carried out to study the cracking characteristics in this alloy. The diffusivity and concentration of hydrogen were obtained from both permeation and cathodic charging/thermal evolution experiments. The cause of cracking by static charging could be attributed to the build up of an internal hydrogen pressure around heterogeneous sites. The critical pressures for crack initiation were calculated based on the diffusivity and concentration data.
The effects of hydrogen on the tensile properties and fracture processes at room temperature were... more The effects of hydrogen on the tensile properties and fracture processes at room temperature were investigated. Specimens were tested at various strain rates in air or under different cathodic charging-current densities. The slopes of the stress-strain curves were essentially identical for all the specimens, except that the fracture points varied under different test conditions. Macroscopically, hydrogen only affected the elastic deformation behavior, but microscopically, the embrittlement was caused by the heterogeneous nucleation of localized plastic deformation. The degree of hydrogen embrittlement increased as the charging current increased or as the strain rate decreased. With the same charging current and time, longer dynamic charging resulted in more severe embrittlement. Before fracture took place, the strength of the alloy could be completely restored if hydrogen had been removed. Hydrogen diffusivity and solubility were used to draw the time-dependent hydrogen concentration profiles for the specimens under different charging conditions. The difference in the mechanical properties was correlated with the hydrogen concentration within the specimen.
Hydrogen-induced slow crack growth (SCG) was compared in austenitic and ferritic stainless steels... more Hydrogen-induced slow crack growth (SCG) was compared in austenitic and ferritic stainless steels at 0 to 125 °Cand 11 to 216 kPa of hydrogen gas. No SCG was observed for AISI 310, while AISI 301 was more susceptible to hydrogen embrittlement and had higher cracking velocity than AL 29-4-2 under the same test conditions. The kinetics of crack propagation was modeled in terms of the hydrogen transport in these alloys. This is a function of temperature, microstructure, and stress state in the embrittlement region. The relatively high cracking velocity of AISI 301 was shown to be controlled by the fast transport of hydrogen through the stress-induced alpha' martensite at the crack tip and low escape rate of hydrogen through the gamma phase in the surrounding region. Faster accumulation rates of hydrogen in the embrittlement region were expected for AISI 301, which led to higher cracking velocities. The mechanism of hydrogen-induced SCG was discussed based upon the concept of hydrogen-enhanced plasticity.
The kinetics of hydrogen-induced slow crack growth (SCG) under constant load was studied in two s... more The kinetics of hydrogen-induced slow crack growth (SCG) under constant load was studied in two stainless steel alloys containing mixtures of bcc and fcc phases. FERRALIUM 255, a duplex stainless steel, consisting of ∼50 pct austenite in a ferrite matrix, was tested in hydrogen gas at 0 to 100 °C with the loading axis both perpendicular and parallel to the rolling direction. In addition, specimens of AISI 301 were deformed in air in different ways to produce various amounts of bcc phase in an austenite matrix prior to testing in H2 gas at room temperature. The kinetics of subcritical slow crack growth (SCG) in these alloys was compared with that for austenitic and for ferritic stainless steels. The SCG rates were rationalized in terms of differences in hydrogen permeation in the two phases. The results confirm that a higher rate of supply and accumulation of hydrogen in the region ahead of the crack tip allows a higher cracking velocity.
Hydrogen diffusivity and permeability in three austenitic iron-based alloys at 200-350 °C were me... more Hydrogen diffusivity and permeability in three austenitic iron-based alloys at 200-350 °C were measured using a gas phase permeation technique. The results were compared with those for AISI 300 series austenitic stainless steels. It was found that hydrogen diffusivity and permeability in all these alloys were very nearly the same. The effects of hydrogen gas on the mechanical properties, especially on the fracture mode and the possibility of hydrogen-induced cracking in these alloys, were investigated and compared. Two of the alloys which had a high manganese content were fairly insensitive to hydrogen damage under our experimental conditions, whereas a high Cu-N substitute for AISI 301 was severely degraded in hydrogen gas near room temperature. The different effects of hydrogen in these alloys are discussed on the basis of hydrogen transport and the stability of their austenitic structure.
... Authors: Husain Khan, Zishan; Husain, M.; Perng, TP; Salah, Numan; Habib, Sami. Affiliation: ... more ... Authors: Husain Khan, Zishan; Husain, M.; Perng, TP; Salah, Numan; Habib, Sami. Affiliation: AA(Center of Nanotechnology, King Abdul Aziz University, Jeddah, The Kingdom of Saudi Arabia ; Department of Applied Sciences and Humanities, Faculty of Engineering and ...
Pt/SnO 2 core-shell nanowires were prepared by a process that involves thermal evaporation of SnO... more Pt/SnO 2 core-shell nanowires were prepared by a process that involves thermal evaporation of SnO 2 nanowires and subsequent atomic layer deposition of Pt, and their gas- and photon-sensing properties were investigated systematically. Transmission electron microscopy analysis showed that the Pt shell with a thickness of 8.8 nm is composed of numerous Pt nanoparticles with average diameters of ∼5.3 nm. The Pt/SnO 2 core-shell nanowires with high electrical conductance exhibit remarkably enhanced ethanol gas- and photon-sensing properties due to the surface functionalization resulting from the effective Pt catalyst and the formation of hetero-nanostructures fabricated by the SnO 2 core and Pt shell.
The stresses induced by hydrogen absorption in Pd nanofilms were studied by the electrochemical q... more The stresses induced by hydrogen absorption in Pd nanofilms were studied by the electrochemical quartz crystal microbalance (EQCM) and bending beam methods. In the EQCM method, hydrogen was charged electrolytically into a Pd nanofilm that was coated on an AT-or BT-cut quartz crystal. For Pd films in a thickness of 120-nm on the AT-cut and 158-nm on the BT-cut quartz crystal, compressive stresses 3 3 of 1.07310 MPa and 1.70310 MPa, respectively, were measured. With the bending beam technique, the bending curvature of the Si substrate during gas-phase hydrogenation was monitored. The maximum compressive stress induced in a 50-nm Pd film on the Si substrate during hydrogenation at 0.2 MPa of hydrogen gas was 944 MPa. When hydrogen was desorbed from the film, a tensile stress of 708 MPa in the film was observed. When the thickness of the Pd film was increased to 130 nm, peeling of the Pd film from the substrate occurred.
The hydrogenation properties of TiFe, TiFe and pure Ti during high-energy ball milling in hydroge... more The hydrogenation properties of TiFe, TiFe and pure Ti during high-energy ball milling in hydrogen atmosphere were studied. By ball 2 milling, TiFe could absorb hydrogen without activation treatment. For Ti powder, a single phase TiH was formed. In addition, TiFe 1.924 2 could also be hydrided by ball milling in hydrogen, which was ascribed to decomposition to form TiFeH , TiH , and Fe. Based on the x 1.924 hydrogenation properties of Ti, TiFe, and TiFe during dynamic ball milling and the thermal stability of the milled powders, it is proposed 2 that the reactions in the milling of TiFe in hydrogen involve four steps: (1) fresh surfaces created by collision with the balls; (2) absorption of hydrogen by the powder; (3) oversaturation of hydrogen in the powder; (4) decomposition of TiFeH to TiH and Fe.
An AB2-type alloy ZrMn0.6V0.2Co0.1Ni1.2 was sintered with Ag powder to form a durable pellet. The... more An AB2-type alloy ZrMn0.6V0.2Co0.1Ni1.2 was sintered with Ag powder to form a durable pellet. The aim is to fabricate a metal hydride electrode that can be rapidly charged with hydrogen gas and then discharged as an anode for Ni–hydride battery in electrolyte. The alloy in the pellet maintains the C15 Laves phase structure without forming a second phase. For the
A series of multicomponent Zr-base AB 2 alloys (Zr-Mn-Ni, Zr-Ti-Mn-Ni, Zr-Mn-V-Ni, and Zr-Mn-V-Co... more A series of multicomponent Zr-base AB 2 alloys (Zr-Mn-Ni, Zr-Ti-Mn-Ni, Zr-Mn-V-Ni, and Zr-Mn-V-Co-Ni) were prepared. The major phase in the alloys had a C15-type structure with the lattice parameter varying with the atomic radii of A and B atoms. Absorption and desorption of hydrogen gas were performed in a Sievert's apparatus. The kinetics of the first few cycles of hydriding-dehydriding was collected. The P-C-T curves were also established for these alloys. It was found that these kinetic and thermodynamic properties were highly dependent on the solid solution in atomic site of A or B. The hydrogenation properties are explained based on the composition, the alloying element, and the free cell volume of the alloys.
An AB5-type hydrogen storage alloy, LaNi4.25Al0.15Co0.5V0.1, was mixed with Ag flakes or Ni powde... more An AB5-type hydrogen storage alloy, LaNi4.25Al0.15Co0.5V0.1, was mixed with Ag flakes or Ni powder, pressed, and sintered to fabricate a durable pellet that would maintain its integrity during repeated gas phase or electrochemical hydriding and dehydriding. The molar compositions Ag/AB5⩾10 and Ni/AB5⩾25 could meet this requirement. After sintering, the alloy in the pellet Ag/AB5=10 maintains the original phases, but a
Silicon nanoparticles with diameters ranging from 3 to 50 nm were prepared by thermal evaporation... more Silicon nanoparticles with diameters ranging from 3 to 50 nm were prepared by thermal evaporation. The nanoparticles showed visible light emissions from 5000 A to 9000 A, with peak intensity at 8000-8200 A, when excited with a He-Cd laser. The intensity increased with decreasing particle size. Based on the photoluminescence (PL) characteristics, it is suggested that the PL for particles larger than 9 nm is surface state-induced, while the PL for those smaller than 9 nm is ascribed to quantum confinement effects.
An electrochemical technique was used to study the effects of elastic stress on hydrogen permeati... more An electrochemical technique was used to study the effects of elastic stress on hydrogen permeation in AL 2% 4-2 ferritic stainless steel. Tensile stress increased the permeability. The change in diffusivity induced by the stress was relatively inconsistent, but the activation energy consistently increased. The average partial molar volume of hydrogen deduced from the increased hydrogen flux at 40-60 "C was 2.3 cm3 mol-'.
TiO2 multi-walled nanotube arrays (MWNTAs) were synthesized by atomic layer deposition (ALD) usin... more TiO2 multi-walled nanotube arrays (MWNTAs) were synthesized by atomic layer deposition (ALD) using anodic aluminum oxide (AAO) as the template. TiO2 and Al2O3 layers were alternately deposited into the AAO pores by ALD. The tube thickness and the gap span were controlled by the ALD cycle numbers of TiO2 and Al2O3, respectively. A MWNT composed of two or three concentric tubes with different diameters was formed after removal of Al2O3. Silver nanoparticles were then deposited on both inner and outer surfaces of the tubes by photochemical reduction. Degradation of methylene blue was carried out to evaluate the photocatalytic activity of bare and silver-loaded TiO2 MWNTAs. It was found that the amount of TiO2, the reaction surface area, the crystalline phase, and silver modification were the factors to determine the photocatalytic activity. The triple-walled MWNTAs showed the best performance, and Ag loading further enhanced the activity.
Atomic layer deposition (ALD) has been widely used to prepare high-k dielectric films for metalo... more Atomic layer deposition (ALD) has been widely used to prepare high-k dielectric films for metaloxidesemiconductor field-effect transistors and the capacitor layer of dynamic random-access memory.1 The self-limiting gassolid reaction of ALD processes enables ...
... [6] ON Senkov and FH Froes, Int. J. Hydrogen Energy 24 (1999), p. 565. Article | PDF (390 K) ... more ... [6] ON Senkov and FH Froes, Int. J. Hydrogen Energy 24 (1999), p. 565. Article | PDF (390 K) | View Record in Scopus | Cited By in Scopus (113). [7] D. Eliezer, N. Eliaz, ON Senkov and FH Froes, Mater. Sci. Eng. A 280 (2000), p. 220. Article | PDF (101 K) |.
Carbon nanotubes have been synthesized by a LPCVD on nanocrystalline Fe-Pd film. CNTs are grown f... more Carbon nanotubes have been synthesized by a LPCVD on nanocrystalline Fe-Pd film. CNTs are grown for 30 min and 1 h respectively. From the SEM images, the diameter of these nanotubes varies from 40-80 nm and the length is several micro-meter approximately. TEM observations suggest that the CNTs are multi-walled and the structure changes from ordinary geometry of CNTs to bamboo shaped. We have observed sharp G and D bands in the Raman spectra of these carbon nanotubes. Higher D-band is observed for the carbon nanotubes grown for longer time (1 h), showing that these nanotubes contain more amorphous carbon. The field emission measurements for these CNTs are also performed. For CNTs grown for longer time (1 h), a superior turn-on field of 4:88 V=mm (when the current density achieves 10 mA=cm 2) is obtained and a current density of 29:36 mA=cm 2 can be generated at 9:59 V=mm.
Cracking in amorphous ribbon of Fe40Ni38Mo4B18 without external loading could be induced by catho... more Cracking in amorphous ribbon of Fe40Ni38Mo4B18 without external loading could be induced by cathodic charging with hydrogen in 0.1 N H2SO4 + 5 mg/L NaAsO2. However, before cracking was initiated, the effect of hydrogen on the mechanical properties could be eliminated if hydrogen had been removed. A series of static charging experiments was carried out to study the cracking characteristics in this alloy. The diffusivity and concentration of hydrogen were obtained from both permeation and cathodic charging/thermal evolution experiments. The cause of cracking by static charging could be attributed to the build up of an internal hydrogen pressure around heterogeneous sites. The critical pressures for crack initiation were calculated based on the diffusivity and concentration data.
The effects of hydrogen on the tensile properties and fracture processes at room temperature were... more The effects of hydrogen on the tensile properties and fracture processes at room temperature were investigated. Specimens were tested at various strain rates in air or under different cathodic charging-current densities. The slopes of the stress-strain curves were essentially identical for all the specimens, except that the fracture points varied under different test conditions. Macroscopically, hydrogen only affected the elastic deformation behavior, but microscopically, the embrittlement was caused by the heterogeneous nucleation of localized plastic deformation. The degree of hydrogen embrittlement increased as the charging current increased or as the strain rate decreased. With the same charging current and time, longer dynamic charging resulted in more severe embrittlement. Before fracture took place, the strength of the alloy could be completely restored if hydrogen had been removed. Hydrogen diffusivity and solubility were used to draw the time-dependent hydrogen concentration profiles for the specimens under different charging conditions. The difference in the mechanical properties was correlated with the hydrogen concentration within the specimen.
Hydrogen-induced slow crack growth (SCG) was compared in austenitic and ferritic stainless steels... more Hydrogen-induced slow crack growth (SCG) was compared in austenitic and ferritic stainless steels at 0 to 125 °Cand 11 to 216 kPa of hydrogen gas. No SCG was observed for AISI 310, while AISI 301 was more susceptible to hydrogen embrittlement and had higher cracking velocity than AL 29-4-2 under the same test conditions. The kinetics of crack propagation was modeled in terms of the hydrogen transport in these alloys. This is a function of temperature, microstructure, and stress state in the embrittlement region. The relatively high cracking velocity of AISI 301 was shown to be controlled by the fast transport of hydrogen through the stress-induced alpha' martensite at the crack tip and low escape rate of hydrogen through the gamma phase in the surrounding region. Faster accumulation rates of hydrogen in the embrittlement region were expected for AISI 301, which led to higher cracking velocities. The mechanism of hydrogen-induced SCG was discussed based upon the concept of hydrogen-enhanced plasticity.
The kinetics of hydrogen-induced slow crack growth (SCG) under constant load was studied in two s... more The kinetics of hydrogen-induced slow crack growth (SCG) under constant load was studied in two stainless steel alloys containing mixtures of bcc and fcc phases. FERRALIUM 255, a duplex stainless steel, consisting of ∼50 pct austenite in a ferrite matrix, was tested in hydrogen gas at 0 to 100 °C with the loading axis both perpendicular and parallel to the rolling direction. In addition, specimens of AISI 301 were deformed in air in different ways to produce various amounts of bcc phase in an austenite matrix prior to testing in H2 gas at room temperature. The kinetics of subcritical slow crack growth (SCG) in these alloys was compared with that for austenitic and for ferritic stainless steels. The SCG rates were rationalized in terms of differences in hydrogen permeation in the two phases. The results confirm that a higher rate of supply and accumulation of hydrogen in the region ahead of the crack tip allows a higher cracking velocity.
Hydrogen diffusivity and permeability in three austenitic iron-based alloys at 200-350 °C were me... more Hydrogen diffusivity and permeability in three austenitic iron-based alloys at 200-350 °C were measured using a gas phase permeation technique. The results were compared with those for AISI 300 series austenitic stainless steels. It was found that hydrogen diffusivity and permeability in all these alloys were very nearly the same. The effects of hydrogen gas on the mechanical properties, especially on the fracture mode and the possibility of hydrogen-induced cracking in these alloys, were investigated and compared. Two of the alloys which had a high manganese content were fairly insensitive to hydrogen damage under our experimental conditions, whereas a high Cu-N substitute for AISI 301 was severely degraded in hydrogen gas near room temperature. The different effects of hydrogen in these alloys are discussed on the basis of hydrogen transport and the stability of their austenitic structure.
... Authors: Husain Khan, Zishan; Husain, M.; Perng, TP; Salah, Numan; Habib, Sami. Affiliation: ... more ... Authors: Husain Khan, Zishan; Husain, M.; Perng, TP; Salah, Numan; Habib, Sami. Affiliation: AA(Center of Nanotechnology, King Abdul Aziz University, Jeddah, The Kingdom of Saudi Arabia ; Department of Applied Sciences and Humanities, Faculty of Engineering and ...
Pt/SnO 2 core-shell nanowires were prepared by a process that involves thermal evaporation of SnO... more Pt/SnO 2 core-shell nanowires were prepared by a process that involves thermal evaporation of SnO 2 nanowires and subsequent atomic layer deposition of Pt, and their gas- and photon-sensing properties were investigated systematically. Transmission electron microscopy analysis showed that the Pt shell with a thickness of 8.8 nm is composed of numerous Pt nanoparticles with average diameters of ∼5.3 nm. The Pt/SnO 2 core-shell nanowires with high electrical conductance exhibit remarkably enhanced ethanol gas- and photon-sensing properties due to the surface functionalization resulting from the effective Pt catalyst and the formation of hetero-nanostructures fabricated by the SnO 2 core and Pt shell.
The stresses induced by hydrogen absorption in Pd nanofilms were studied by the electrochemical q... more The stresses induced by hydrogen absorption in Pd nanofilms were studied by the electrochemical quartz crystal microbalance (EQCM) and bending beam methods. In the EQCM method, hydrogen was charged electrolytically into a Pd nanofilm that was coated on an AT-or BT-cut quartz crystal. For Pd films in a thickness of 120-nm on the AT-cut and 158-nm on the BT-cut quartz crystal, compressive stresses 3 3 of 1.07310 MPa and 1.70310 MPa, respectively, were measured. With the bending beam technique, the bending curvature of the Si substrate during gas-phase hydrogenation was monitored. The maximum compressive stress induced in a 50-nm Pd film on the Si substrate during hydrogenation at 0.2 MPa of hydrogen gas was 944 MPa. When hydrogen was desorbed from the film, a tensile stress of 708 MPa in the film was observed. When the thickness of the Pd film was increased to 130 nm, peeling of the Pd film from the substrate occurred.
The hydrogenation properties of TiFe, TiFe and pure Ti during high-energy ball milling in hydroge... more The hydrogenation properties of TiFe, TiFe and pure Ti during high-energy ball milling in hydrogen atmosphere were studied. By ball 2 milling, TiFe could absorb hydrogen without activation treatment. For Ti powder, a single phase TiH was formed. In addition, TiFe 1.924 2 could also be hydrided by ball milling in hydrogen, which was ascribed to decomposition to form TiFeH , TiH , and Fe. Based on the x 1.924 hydrogenation properties of Ti, TiFe, and TiFe during dynamic ball milling and the thermal stability of the milled powders, it is proposed 2 that the reactions in the milling of TiFe in hydrogen involve four steps: (1) fresh surfaces created by collision with the balls; (2) absorption of hydrogen by the powder; (3) oversaturation of hydrogen in the powder; (4) decomposition of TiFeH to TiH and Fe.
An AB2-type alloy ZrMn0.6V0.2Co0.1Ni1.2 was sintered with Ag powder to form a durable pellet. The... more An AB2-type alloy ZrMn0.6V0.2Co0.1Ni1.2 was sintered with Ag powder to form a durable pellet. The aim is to fabricate a metal hydride electrode that can be rapidly charged with hydrogen gas and then discharged as an anode for Ni–hydride battery in electrolyte. The alloy in the pellet maintains the C15 Laves phase structure without forming a second phase. For the
A series of multicomponent Zr-base AB 2 alloys (Zr-Mn-Ni, Zr-Ti-Mn-Ni, Zr-Mn-V-Ni, and Zr-Mn-V-Co... more A series of multicomponent Zr-base AB 2 alloys (Zr-Mn-Ni, Zr-Ti-Mn-Ni, Zr-Mn-V-Ni, and Zr-Mn-V-Co-Ni) were prepared. The major phase in the alloys had a C15-type structure with the lattice parameter varying with the atomic radii of A and B atoms. Absorption and desorption of hydrogen gas were performed in a Sievert's apparatus. The kinetics of the first few cycles of hydriding-dehydriding was collected. The P-C-T curves were also established for these alloys. It was found that these kinetic and thermodynamic properties were highly dependent on the solid solution in atomic site of A or B. The hydrogenation properties are explained based on the composition, the alloying element, and the free cell volume of the alloys.
An AB5-type hydrogen storage alloy, LaNi4.25Al0.15Co0.5V0.1, was mixed with Ag flakes or Ni powde... more An AB5-type hydrogen storage alloy, LaNi4.25Al0.15Co0.5V0.1, was mixed with Ag flakes or Ni powder, pressed, and sintered to fabricate a durable pellet that would maintain its integrity during repeated gas phase or electrochemical hydriding and dehydriding. The molar compositions Ag/AB5⩾10 and Ni/AB5⩾25 could meet this requirement. After sintering, the alloy in the pellet Ag/AB5=10 maintains the original phases, but a
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