Greg Gruzalski - Academia.edu (original) (raw)
Papers by Greg Gruzalski
Journal of Nanoscience and Nanotechnology, 2012
Tungsten, titanium, tantalum, aluminum carbides nanoparticles were produced by electrical explosi... more Tungsten, titanium, tantalum, aluminum carbides nanoparticles were produced by electrical explosion of wires. The explosions were carried out in gaseous mixtures of argon and acetylene at different ratios, argon and propane, and in liquids such as benzene, toluene, decane. The effects of the synthesis conditions on the size and phase composition of metal carbide nanoparticles were investigated. The thermal activity of the prepared powders was studied by the method of differential thermal analysis at the heating in air. Thermodynamic analysis of carbides formation during the process of electrical explosion has been made. The output of the chemical compounds depends on their thermal stability: the more thermally stable they are, the higher their output.
Ceramics International, 2007
In the present study, hydrogen evolution reaction (HER) by alkaline water electrolysis was conduc... more In the present study, hydrogen evolution reaction (HER) by alkaline water electrolysis was conducted without using a precious metal catalyst. We synthesized an amorphous cobalt-doped molybdenum sulfide by electrodeposition using different cobalt loadings. The amorphous Co-MoS x produced was characterized by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The cobalt doping and sulfidation procedure resulted in the successful fabrication of a candidate catalyst for the catalytic hydrogen evolution in alkaline solution with high intrinsic activity. Cobalt incorporated amorphous MoS x exhibited 3 times higher HER activity than non-promoted MoS x .
MAGNETISM AND MAGNETIC MATERIALS — 1973: Nineteenth Annual Conference
Electronic and magnetic properties were investigated in the amorphous metallic alloys Zr40Cu60-xF... more Electronic and magnetic properties were investigated in the amorphous metallic alloys Zr40Cu60-xFex for 0 <= x <= 12. Evidence was obtained for spin fluctuation phenomena in the host alloy (x = 0) and for local moment behavior associated with Fe impurities. Resistance maxima are observed at higher Fe concentrations but, in general, the behavior is different from that exhibited by typical crystalline spin glasses.
Amorphous Magnetism II
Magnetic properties of amorphous and crystalline Zr40Cu60-xFex, amorphous Zr40Cu54Gd6, and amorph... more Magnetic properties of amorphous and crystalline Zr40Cu60-xFex, amorphous Zr40Cu54Gd6, and amorphous Nb50Ni50-xFex alloys are described, and the nature of the magnetic coupling in these alloys is discussed. None of these alloys exhibit spin-glass phenomena. There are localized magnetic moments on the Fe and Gd atoms and these lead to ferromagnetism in Zr40Cu48Fe12 and Zr40Cu54Gd6. The Nb50Ni50-xFex system shows some spin clustering effects but no magnetic order up to x = 10.
Thin film amorphous electrolytes with compositions xLi{sub 2}O: ySiO{sub 2}:zP{sub 2}O{sub 5} wer... more Thin film amorphous electrolytes with compositions xLi{sub 2}O: ySiO{sub 2}:zP{sub 2}O{sub 5} were deposited by single and dual source rf magnetron sputtering and their compositions determined by electron and ion beam techniques. Films containing P but no Si were composed of mainly orthophosphate and some linear chain phosphate anions, whereas single phase films containing Si and P were evidently composed of branched and possible cyclic and extended network structures. Films with Si/P>1 appeared to contain two or more amorphous phases. In the range of compositions investigated, the lithium ion conductivity depends mainly on the lithium ion mobility which is sensitive to the structure of the films. An open circuit voltage from 1 to 3 V measured between blocking metal contacts on the electrolyte thin films suggest that the films might be electrets. 18 refs., 5 figs., 2 tabs.
Surface Science
Using angle-resolved ultraviolet photoemission spectroscopy with synchrotron radiation, the absol... more Using angle-resolved ultraviolet photoemission spectroscopy with synchrotron radiation, the absolute work functions of four (100) surfaces having estimated compositions TaC,.e, TaCos, HfCr.a, and HfC& were determined to be 4.38, 4.73, 4.63, and 3.87 eV, respectively. The results are interpreted qualitatively by considering the work function as a sum of two terms, one which arises from the presence of a surface dipole layer and another which is associated with the Fermi level. The difference in work-function bebavior (its increasing with carbon content x for HfC, but d-sing with x for TaC,) is shown to be-ted with a difference in Fermi-level behavior. In a recently published XPS study [l] of HfC, (0.6 gx 5 1.0) and TaC, (0.5 5.x s IO), it was found that, as the carbon content x decreased, the Fermi level moved higher in the bands for HfC, and lower in the bands for TaC,. Because it was felt that this behavior could be detected by workfunction measurements, such measurements were performed on four (100) surfaces having nearsurface ~mpo~tio~s estimated as
Solid State Communications
Physical Review B
We consider the random anisotropy model for amorphous magnetism by making a local-mean-field appr... more We consider the random anisotropy model for amorphous magnetism by making a local-mean-field approximation (LMFA) on arrays of spin-one particles. Hysteresis loops and the temperature (T) dependence of several thermodynamic quantities are presented for various values of the ratio of the strength of the exchange (J) to the strength of the uniaxial anisotropy (D). Using the LMFA limits us to systems with a small nuinber (N) of spina, of which we explicitly consider N = 64, 216, and 1000. We assume periodic boundary conditions on a system with N'" spins along an edge, nearest-neighbor coupling of constant strength, and six nearest neighbors (as for a simple cubic lattice). For J & 0 the free energy of spin-glasslike states is higher than that of corresponding states with remanent magnetization. The dependence of the coercive field (B,) on J and D is discussed and the apparent discrepancy of Chi and Alben vis d vis Callen, Liu, and Cullen concerning the behavior of B, for large D is clarified. A calculation of the temperature dependence of B, is presented which is reminiscent of experimental results. This random anisotropy is found to give rise to a second peak in the specific heat for suitable values of D/J. The magnetic susceptibility Qr) is calculated for both positive and negative jand shows positive and negative paramagnetic Curie-Weiss temperatures, respectively. The slopes of the gz '(T) curves for T well above the critical temperature (T,) have values that are roughly equal to 3/2, the value appropriate to D = 0 and 5 = 1. The local order parameter q is used to identify T"which correlates well with the critical temperature identified from other thermodynamic quantities. The presence of the random anisotropy is found to reduce T, by up to about 2S%. The results of several temperature-dependent calculations are summarized in a phase diagram and regions of paramagnetic, random ferromagnetic, and random antiferromagnetic (or spin-glass-like) behavior are identified.
Journal of the Optical Society of America
The equations governing ellipsometry measurements made with a photoelastic modulator are presente... more The equations governing ellipsometry measurements made with a photoelastic modulator are presented in a simple but general form. These equations are used to study the propagation of both systematic and random errors, and an assessment of the accuracy of the ellipsometer is made. A basis is provided for choosing among various ellipsometer configurations, measurement procedures, and methods of data analysis. Several new insights into the performance of this type of ellipsometer are supplied.
Physical Review B
The diffusion and electromigration of copper in lead-tin alloys containing up to 12 at. % Sn have... more The diffusion and electromigration of copper in lead-tin alloys containing up to 12 at. % Sn have been studied for sample temperatures between 100 and 317'C. The diffusion measurements were made by the standard sequential-sectioning technique, adapted to the 12.8-h half-life of the isotope Cu. The rapid decrease of copper diffusivity with increasing concentration of tin is interpreted as evidence for trapping with a binding energy of about 0.3 eV. Purity of the lead solvent proved to be very important in measuring the low-temperature diffusivity. Although our values of the copper diffusivity in "pure" lead are slightly higher than other reported values, our Arrhenius curves tend to fall at the lowest temperatures, showing the effect of trapping by minute amounts of unwanted impurities. The solubility of copper in the lead and in the lead-tin alloys was determined from those diffusion measurements where the surface concentration exceeded the solubility limit. One feature which is still under investigation is that, at low temperatures, the diffusivity as a function of tin content goes through a minimum and then increases perceptibly. The electromigration results were obtained by the steady-state method. The effective charge number for copper was determined to be about unity, independent of tin concentration. In other words, the electromigration force on the mobile atoms is unchanged by the trapping phenomenon, although, of course, the time to reach equilibrium is prolonged.
Solid State Ionics
The ~mpedance of xL~20 yS~O~, zP205 thin films deposited by RF-magnetron sputtering was analyzed ... more The ~mpedance of xL~20 yS~O~, zP205 thin films deposited by RF-magnetron sputtering was analyzed using two models m which the frequency dependence of the bulk response was represented by (1) a Cole-Cole &electrzc functmn and (2) a constant phase angle element. Increases m the conductlv~t) w]th L120 concentration and with addition of S]O2 to L~20-P205 composmons are attributed to an increase m L~ + mobility caused by changes m the film structure. ~ new amorphous oxymtnde electrolyte, Ll33PO3 9No iT, prepared by sputtering LI3PO4 In N 2, has a conductlv lty at 25 °C of 2 × 10-~ S/cm and is stable m contact with hthmm
![Research paper thumbnail of Electronic and magnetic properties of amorphous Fe--P--B alloys. [75 to 83 at. % Fe]](https://attachments.academia-assets.com/77395334/thumbnails/1.jpg)
](
Described is a thin-film battery, especially a thin-film microbattery, and a method for making sa... more Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode. Configured as a microbattery, the battery can be
Described is a thin-film battery, especially a thin-film microbattery, and a method for making sa... more Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be
MRS Proceedings, 1985
ABSTRACTXPS was used to determine core-level binding energies and valence-band structure for TaCx... more ABSTRACTXPS was used to determine core-level binding energies and valence-band structure for TaCx over the range 0.5 ≲ × ≲ 1.0. As x decreased, the carbonls binding energy (BE) changed very little, the carbon-2s BE shifted toward the Fermi level, the position of the p-d valence-band peak shifted toward the Fermi level more, and the tantalum-4d and -4f BE's shifted toward the Fermi level even more, about 0.16 eV for a change in × of 0.1. In addition, the valence-band spectra exhibited structure between about 1 and 2 eV BE, and this structure increased as x decreased. These observations are explicable in terms of charge transfer and the formation of occupied defect states associated with carbon vacancies.
MRS Proceedings, 1990
Thin film amorphous electrolytes with compositions xLi2O:ySiO2:zP2O5 were deposited by single and... more Thin film amorphous electrolytes with compositions xLi2O:ySiO2:zP2O5 were deposited by single and dual source rf magnetron sputtering and their compositions determined by electron and ion beam techniques. Films containing P but no Si were composed of mainly orthophosphate and some linear chain phosphate anions, whereas single phase films containing Si and P were evidently composed of branched and possibly cyclic and extended network structures. Films with Si/P > 1 appeared to contain two or more amorphous phases. In the range of compositions investigated, the lithium ion conductivity depends mainly on the lithium ion mobility which is sensitive to the structure of the films. An open circuit voltage from 1 to 3 V measured between blocking metal contacts on the electrolyte thin films suggests that the films mightbe electrets.
Journal of Nanoscience and Nanotechnology, 2012
Tungsten, titanium, tantalum, aluminum carbides nanoparticles were produced by electrical explosi... more Tungsten, titanium, tantalum, aluminum carbides nanoparticles were produced by electrical explosion of wires. The explosions were carried out in gaseous mixtures of argon and acetylene at different ratios, argon and propane, and in liquids such as benzene, toluene, decane. The effects of the synthesis conditions on the size and phase composition of metal carbide nanoparticles were investigated. The thermal activity of the prepared powders was studied by the method of differential thermal analysis at the heating in air. Thermodynamic analysis of carbides formation during the process of electrical explosion has been made. The output of the chemical compounds depends on their thermal stability: the more thermally stable they are, the higher their output.
Ceramics International, 2007
In the present study, hydrogen evolution reaction (HER) by alkaline water electrolysis was conduc... more In the present study, hydrogen evolution reaction (HER) by alkaline water electrolysis was conducted without using a precious metal catalyst. We synthesized an amorphous cobalt-doped molybdenum sulfide by electrodeposition using different cobalt loadings. The amorphous Co-MoS x produced was characterized by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The cobalt doping and sulfidation procedure resulted in the successful fabrication of a candidate catalyst for the catalytic hydrogen evolution in alkaline solution with high intrinsic activity. Cobalt incorporated amorphous MoS x exhibited 3 times higher HER activity than non-promoted MoS x .
MAGNETISM AND MAGNETIC MATERIALS — 1973: Nineteenth Annual Conference
Electronic and magnetic properties were investigated in the amorphous metallic alloys Zr40Cu60-xF... more Electronic and magnetic properties were investigated in the amorphous metallic alloys Zr40Cu60-xFex for 0 <= x <= 12. Evidence was obtained for spin fluctuation phenomena in the host alloy (x = 0) and for local moment behavior associated with Fe impurities. Resistance maxima are observed at higher Fe concentrations but, in general, the behavior is different from that exhibited by typical crystalline spin glasses.
Amorphous Magnetism II
Magnetic properties of amorphous and crystalline Zr40Cu60-xFex, amorphous Zr40Cu54Gd6, and amorph... more Magnetic properties of amorphous and crystalline Zr40Cu60-xFex, amorphous Zr40Cu54Gd6, and amorphous Nb50Ni50-xFex alloys are described, and the nature of the magnetic coupling in these alloys is discussed. None of these alloys exhibit spin-glass phenomena. There are localized magnetic moments on the Fe and Gd atoms and these lead to ferromagnetism in Zr40Cu48Fe12 and Zr40Cu54Gd6. The Nb50Ni50-xFex system shows some spin clustering effects but no magnetic order up to x = 10.
Thin film amorphous electrolytes with compositions xLi{sub 2}O: ySiO{sub 2}:zP{sub 2}O{sub 5} wer... more Thin film amorphous electrolytes with compositions xLi{sub 2}O: ySiO{sub 2}:zP{sub 2}O{sub 5} were deposited by single and dual source rf magnetron sputtering and their compositions determined by electron and ion beam techniques. Films containing P but no Si were composed of mainly orthophosphate and some linear chain phosphate anions, whereas single phase films containing Si and P were evidently composed of branched and possible cyclic and extended network structures. Films with Si/P>1 appeared to contain two or more amorphous phases. In the range of compositions investigated, the lithium ion conductivity depends mainly on the lithium ion mobility which is sensitive to the structure of the films. An open circuit voltage from 1 to 3 V measured between blocking metal contacts on the electrolyte thin films suggest that the films might be electrets. 18 refs., 5 figs., 2 tabs.
Surface Science
Using angle-resolved ultraviolet photoemission spectroscopy with synchrotron radiation, the absol... more Using angle-resolved ultraviolet photoemission spectroscopy with synchrotron radiation, the absolute work functions of four (100) surfaces having estimated compositions TaC,.e, TaCos, HfCr.a, and HfC& were determined to be 4.38, 4.73, 4.63, and 3.87 eV, respectively. The results are interpreted qualitatively by considering the work function as a sum of two terms, one which arises from the presence of a surface dipole layer and another which is associated with the Fermi level. The difference in work-function bebavior (its increasing with carbon content x for HfC, but d-sing with x for TaC,) is shown to be-ted with a difference in Fermi-level behavior. In a recently published XPS study [l] of HfC, (0.6 gx 5 1.0) and TaC, (0.5 5.x s IO), it was found that, as the carbon content x decreased, the Fermi level moved higher in the bands for HfC, and lower in the bands for TaC,. Because it was felt that this behavior could be detected by workfunction measurements, such measurements were performed on four (100) surfaces having nearsurface ~mpo~tio~s estimated as
Solid State Communications
Physical Review B
We consider the random anisotropy model for amorphous magnetism by making a local-mean-field appr... more We consider the random anisotropy model for amorphous magnetism by making a local-mean-field approximation (LMFA) on arrays of spin-one particles. Hysteresis loops and the temperature (T) dependence of several thermodynamic quantities are presented for various values of the ratio of the strength of the exchange (J) to the strength of the uniaxial anisotropy (D). Using the LMFA limits us to systems with a small nuinber (N) of spina, of which we explicitly consider N = 64, 216, and 1000. We assume periodic boundary conditions on a system with N'" spins along an edge, nearest-neighbor coupling of constant strength, and six nearest neighbors (as for a simple cubic lattice). For J & 0 the free energy of spin-glasslike states is higher than that of corresponding states with remanent magnetization. The dependence of the coercive field (B,) on J and D is discussed and the apparent discrepancy of Chi and Alben vis d vis Callen, Liu, and Cullen concerning the behavior of B, for large D is clarified. A calculation of the temperature dependence of B, is presented which is reminiscent of experimental results. This random anisotropy is found to give rise to a second peak in the specific heat for suitable values of D/J. The magnetic susceptibility Qr) is calculated for both positive and negative jand shows positive and negative paramagnetic Curie-Weiss temperatures, respectively. The slopes of the gz '(T) curves for T well above the critical temperature (T,) have values that are roughly equal to 3/2, the value appropriate to D = 0 and 5 = 1. The local order parameter q is used to identify T"which correlates well with the critical temperature identified from other thermodynamic quantities. The presence of the random anisotropy is found to reduce T, by up to about 2S%. The results of several temperature-dependent calculations are summarized in a phase diagram and regions of paramagnetic, random ferromagnetic, and random antiferromagnetic (or spin-glass-like) behavior are identified.
Journal of the Optical Society of America
The equations governing ellipsometry measurements made with a photoelastic modulator are presente... more The equations governing ellipsometry measurements made with a photoelastic modulator are presented in a simple but general form. These equations are used to study the propagation of both systematic and random errors, and an assessment of the accuracy of the ellipsometer is made. A basis is provided for choosing among various ellipsometer configurations, measurement procedures, and methods of data analysis. Several new insights into the performance of this type of ellipsometer are supplied.
Physical Review B
The diffusion and electromigration of copper in lead-tin alloys containing up to 12 at. % Sn have... more The diffusion and electromigration of copper in lead-tin alloys containing up to 12 at. % Sn have been studied for sample temperatures between 100 and 317'C. The diffusion measurements were made by the standard sequential-sectioning technique, adapted to the 12.8-h half-life of the isotope Cu. The rapid decrease of copper diffusivity with increasing concentration of tin is interpreted as evidence for trapping with a binding energy of about 0.3 eV. Purity of the lead solvent proved to be very important in measuring the low-temperature diffusivity. Although our values of the copper diffusivity in "pure" lead are slightly higher than other reported values, our Arrhenius curves tend to fall at the lowest temperatures, showing the effect of trapping by minute amounts of unwanted impurities. The solubility of copper in the lead and in the lead-tin alloys was determined from those diffusion measurements where the surface concentration exceeded the solubility limit. One feature which is still under investigation is that, at low temperatures, the diffusivity as a function of tin content goes through a minimum and then increases perceptibly. The electromigration results were obtained by the steady-state method. The effective charge number for copper was determined to be about unity, independent of tin concentration. In other words, the electromigration force on the mobile atoms is unchanged by the trapping phenomenon, although, of course, the time to reach equilibrium is prolonged.
Solid State Ionics
The ~mpedance of xL~20 yS~O~, zP205 thin films deposited by RF-magnetron sputtering was analyzed ... more The ~mpedance of xL~20 yS~O~, zP205 thin films deposited by RF-magnetron sputtering was analyzed using two models m which the frequency dependence of the bulk response was represented by (1) a Cole-Cole &electrzc functmn and (2) a constant phase angle element. Increases m the conductlv~t) w]th L120 concentration and with addition of S]O2 to L~20-P205 composmons are attributed to an increase m L~ + mobility caused by changes m the film structure. ~ new amorphous oxymtnde electrolyte, Ll33PO3 9No iT, prepared by sputtering LI3PO4 In N 2, has a conductlv lty at 25 °C of 2 × 10-~ S/cm and is stable m contact with hthmm
Described is a thin-film battery, especially a thin-film microbattery, and a method for making sa... more Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode. Configured as a microbattery, the battery can be
Described is a thin-film battery, especially a thin-film microbattery, and a method for making sa... more Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be
MRS Proceedings, 1985
ABSTRACTXPS was used to determine core-level binding energies and valence-band structure for TaCx... more ABSTRACTXPS was used to determine core-level binding energies and valence-band structure for TaCx over the range 0.5 ≲ × ≲ 1.0. As x decreased, the carbonls binding energy (BE) changed very little, the carbon-2s BE shifted toward the Fermi level, the position of the p-d valence-band peak shifted toward the Fermi level more, and the tantalum-4d and -4f BE's shifted toward the Fermi level even more, about 0.16 eV for a change in × of 0.1. In addition, the valence-band spectra exhibited structure between about 1 and 2 eV BE, and this structure increased as x decreased. These observations are explicable in terms of charge transfer and the formation of occupied defect states associated with carbon vacancies.
MRS Proceedings, 1990
Thin film amorphous electrolytes with compositions xLi2O:ySiO2:zP2O5 were deposited by single and... more Thin film amorphous electrolytes with compositions xLi2O:ySiO2:zP2O5 were deposited by single and dual source rf magnetron sputtering and their compositions determined by electron and ion beam techniques. Films containing P but no Si were composed of mainly orthophosphate and some linear chain phosphate anions, whereas single phase films containing Si and P were evidently composed of branched and possibly cyclic and extended network structures. Films with Si/P > 1 appeared to contain two or more amorphous phases. In the range of compositions investigated, the lithium ion conductivity depends mainly on the lithium ion mobility which is sensitive to the structure of the films. An open circuit voltage from 1 to 3 V measured between blocking metal contacts on the electrolyte thin films suggests that the films mightbe electrets.