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ABSTRACT The photoelectrochemistry of single crystal C60 and fullerene photoelectrochemical solar cells is studied. Illuminated and immersed, C60 is shown to drive oxidation of several solution-phase redox couples. Utilization of a... more
ABSTRACT The photoelectrochemistry of single crystal C60 and fullerene photoelectrochemical solar cells is studied. Illuminated and immersed, C60 is shown to drive oxidation of several solution-phase redox couples. Utilization of a photoelectrochemical solid/liquid junction, rather than solid-state photovoltaic junction, improves the observed photocurrent. Utilization of a single crystal, rather than a polycrystalline film, of C60 decreases dark current to the extent that light-driven charge transfer dominates. The spectral response and current-voltage behaviour in several electrolytes is studied. A low-power fullerene photoelectrochemical solar cell, utilizing a regenerative polyiodide and ferri/ferrocyanide redox couple, is demonstrated.
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Magnetic susceptibility, Mössbauer spectroscopy, nuclear quadrupole resonance of Cu (NQR), nuclear magnetic resonance of Cu in the hyperfine field of the antiferromagnetic state (AFNMR), and x-ray diffraction measurements were performed... more
Magnetic susceptibility, Mössbauer spectroscopy, nuclear quadrupole resonance of Cu (NQR), nuclear magnetic resonance of Cu in the hyperfine field of the antiferromagnetic state (AFNMR), and x-ray diffraction measurements were performed to study the superconducting and magnetic properties of hydrogen charged bulk YBa2Cu4O8Hy. For y<1 the c lattice parameter decreases with y. In contrast to Fe-doped YBa2Cu3O7Hy, where Tc decreases continuously
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The 65Cu and 63Cu NQR lines were obtained at a temperature of 4.2 K for samples of HxYBa2Cu3O7, where x=0.021, 0.058, 0.21, 0.60, and 1.00. New peaks appear upon the introduction of hydrogen. The amplitudes of the various peaks rise and... more
The 65Cu and 63Cu NQR lines were obtained at a temperature of 4.2 K for samples of HxYBa2Cu3O7, where x=0.021, 0.058, 0.21, 0.60, and 1.00. New peaks appear upon the introduction of hydrogen. The amplitudes of the various peaks rise and fall but do not change their positions continuously as x is varied. The positions of the peaks are attributed
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ABSTRACT
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ABSTRACT We extend the theory of growth of the nuclear magnetization in the presence of paramagnetic impurities and the absence of spin diffusion to the case of solids with arbitrary space dimension D. We show that the rate of growth of... more
ABSTRACT We extend the theory of growth of the nuclear magnetization in the presence of paramagnetic impurities and the absence of spin diffusion to the case of solids with arbitrary space dimension D. We show that the rate of growth of the magnetization is proportional to exp(-Atα) where t is the time and α is a fractional power which depends on the concentration and distribution of the paramagnetic centers and the magnetic nuclei. In the homogeneous distribution, α=D/6. In the inhomogeneous distribution, the sample can be regarded as consisting of subsystems packed in the d-dimensional space of the sample, each of which includes a paramagnetic center surrounded by nuclei. This model results in the expression α=(D+d)/6. Experimental data are presented for both of these cases.
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Research Interests:
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ABSTRACT
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We investigate analytically and numerically the multiple-quantum (MQ) NMR dynamics in systems of nuclear spins 1/2 coupled by the dipole-dipole interactions in the case of the dipolar ordered initial state. We suggest two different... more
We investigate analytically and numerically the multiple-quantum (MQ) NMR dynamics in systems of nuclear spins 1/2 coupled by the dipole-dipole interactions in the case of the dipolar ordered initial state. We suggest two different methods of MQ NMR. One of them is based on the measurement of the dipolar temperature in the quasiequilibrium state which is established after the time of order omegaloc-1 ( omegaloc is the dipolar local field) after the MQ NMR experiment. The other method uses an additional resonance (pi/4)y pulse after the preparation period of the standard MQ NMR experiment in solids. Many-spin clusters and correlations are created faster in such experiments than in the usual MQ NMR experiments and can be used for the investigation of many-spin dynamics of nuclear spins in solids.
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... expectation that fullerenes will find practical use in electronics, electrooptics and photovoltaics [2]. However, even in the case of C 60 , the simplest member of the fullerene family, many ... One group of results indicates that the... more
... expectation that fullerenes will find practical use in electronics, electrooptics and photovoltaics [2]. However, even in the case of C 60 , the simplest member of the fullerene family, many ... One group of results indicates that the solid state packing has minimal effect on the ...
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... in air the formation of CO chemical bonds is accompanied by the creation of CC dan-gling bonds ... 18 B. Mishori, EA Katz, D. Faiman, and Y. Shapira, Solid State Commun ... 41 DJ Miller andDR McKenzie, Thin Solid Films 108, 257... more
... in air the formation of CO chemical bonds is accompanied by the creation of CC dan-gling bonds ... 18 B. Mishori, EA Katz, D. Faiman, and Y. Shapira, Solid State Commun ... 41 DJ Miller andDR McKenzie, Thin Solid Films 108, 257 (1983); K. Kaneto, K. Rikitake, T. Aktyama, and ...
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The antiferromagnetic compounds produced by the reaction of the 123 and 124 HTc superconductors with hydrogen are studied by nuclear resonancee of copper. For the 123 compounds two reactions are possible, the reduction by hydrogen which... more
The antiferromagnetic compounds produced by the reaction of the 123 and 124 HTc superconductors with hydrogen are studied by nuclear resonancee of copper. For the 123 compounds two reactions are possible, the reduction by hydrogen which leads to the normal antiferromagnetic YBa2Cu3O6, and the solution of hydrogen in YBa2Cu3O7 which forms a different antiferromagnetic structure with hydrogen concentration of more than 2 H mol−1. Both structures can be distinguished by the nuclear quadrupole resonance spectra of the Cu(1) sites and the nuclear magnetic resonance spectra in the hyperfine field of the antiferromagnetic state. By using samples containing Gd at the place of Y we can prove that only the Cu(2) sites carry permanent magnetic moments. In the hydrogen loaded YBa2Cu4O8 the situation is similar with the antiferromagnetic order limited to the Cu(2) sites.