Search

In this work the groundwork is laid for characterizing the mobility of hydrogen-hydrogen pairs (proton-proton radial vectors) in proteins in the solid state that contain only residual water. In this novel approach, we introduce new ways of analyzing and interpreting data: 1) by representing hydrogen mobility (HM) and melting diagram (MD) data recorded by wide-line 1 H NMR spectroscopic analysis as a function of fundamental temperature (thermal excitation energy); 2) by suggesting a novel mode of interpretation of these parameters that sheds light on details of protein-water interactions, such as the exact amount of water molecules and the distribution of barrier potentials pertaining to their rotational and surface translational mobility; 3) by relying on directly determined physical observables. We illustrate the power of this approach by studying the behavior of two proteins, the structured enzyme lysozyme and the intrinsically disordered ERD14.

Crystalline Pd 1-x Ag x -H y (x = 0-0.35) alloys were studied as model systems representing a chemically disordered system for hydrogen-storage materials. Extensive 1 H relaxation rate (R 1 , R 1p and R 2 ) measurements were carried out in a wide temperature range of 2.4-400 K. Palladium-silver alloys of silver concentration as high as 35 at.% were studied by NMR spectroscopy for the first time. The relaxation mechanisms magnetic dipolar relaxation (hydrogen diffusion), Korringa relaxation, relaxation by paramagnetic impurity ions and cross-relaxation to quadrupolar metal nuclei were identified and characterized. The presence of cross-relaxation between 1 H and quadrupolar 105 Pd nuclear spins was assumed and demonstrated for the first time in Pd-H and Pd 1-x Ag x -H systems. More than one jump processes of diffusing hydrogen were found to be present in the studied palladium-silver alloys. Only lower estimated limit values of Korringa constants could be obtained since no frequency independent R 1 versus T region was found. These values are significantly higher than the ones reported by others.

In this work, the electrochemical hydrogen doping and withdrawal process of Pd metal was examined with respect to the applicability of Faraday’s law. It was found that after a suitable electrolytic pre-treatment, the normalized resistivity ( R / R 0 ) versus hydrogen concentration ( c F = H/M) curves where c F was determined from Faraday’s law by assuming that the 100% current efficiency is independent of the value of the applied charging current density in a wide range. In the α-Pd(H) phase (up to c (α max ) = 0.015H/M), a good quantitative agreement was found with previous resistivity studies by both electrolytic and gas-phase charging. However, for c > c (α max ) our R / R 0 versus c F data did not agree with the R / R 0 versus c H curve from previously reported electrochemical charging experiments of Pd metal where the doped amount of hydrogen, c H , was determined by direct methods. The two sets of resistivity data can be brought into good agreement by assuming that the current efficiency for the absorption process is η a = 1.55. Similarly, for the electrolytic desorption process, an agreement with the previously reported R / R 0 versus c H curve could be achieved by taking η d = 1.9. These current efficiency values higher than unity would imply that each hydrogen absorbed/desorbed by electrolytic charge/discharge processes is accompanied by the absorption/desorption of some excess H atoms by processes not requiring electric charge transfer (i.e., only neutral H atoms are involved). At present, we do not have a physical/chemical picture about the nature of such processes.

The partition of hydrogen into diffusible and residual parts was realized by pulse NMR spectroscopy, by gas chromatography and by prompt gamma activation analysis (PGAA). The total hydrogen content was determined by the two non-NMR methods and the diffusible (mobile) component by CPMG NMR pulse sequence. Results on amorphous Ni(Cu)–Zr–H systems of different compositions are shown. Partially crystallized samples were also studied as an extension. A method proposed by us directly gives the fractional population of hydrogen atoms in the free (mobile) state on the spin–spin relaxation time scale. On the other hand the least values of the residual hydrogen content correlate surprisingly well with the numbers of filled four Zr-type H-sites calculated by Batalla et al. [NATO ASI Ser. 136 (1985) 203] for 0.21-nm exclusion distance.

Simultaneous realisation of hydrogen charging or discharging process and in situ measurements of different NMR characteristic quantities give outstanding chances for the investigation and understanding of local physical properties of and hydrogen diffusion in dis- ordered metal-hydrogen systems, including both equilibrium and non-equilibrium states. A few selected preliminary experimental results are presented in this letter for Pd0.9Ag0.1-H al- loy on in situ hydrogen concentration, proton NMR line-shift and magnetic susceptibility, 1 H NMR spectrum, spin-spin relaxation time and hydrogen diffusion activation energy and cor- relation time measurements. The motional averaged spectrum is asymmetric and the possible decompositions relate to the non-single-site residence of hydrogen in this alloy. Introduction. - Feenstra et al. (1) recently proposed to consider hydrogen embedded in a metallic lattice as a "local probe" for the investigation of local properties of hydrogen containing disordered alloys. In this concept Solomons and co-workers (2) used thermodynamic data of hydrogen absorption for Pd-Ag-H alloys and a multi-site lattice-gas model for the determination of site energies of hydrogen located in the centre of Pd1−xAgx octahedron, and the terminology of "hydrogen spectroscopy" was introduced by them. The Pd-Ag alloys are probably the simplest and consequently the best representatives of the chemically disordered alloys, they were subjects of widespread experimental and the- oretical investigations (see, e.g., (3-5) and references therein). The atomic size of the two alloying elements are nearly the same in this system, and Pd and Ag form homogenous solid solution of face-centred-cubic (fcc) structure in the whole concentration range. The hydrogen solubilities for the pure metals differ by many orders of magnitude, so the local distribution of constituents (probably binomial) could strongly affect the microscopic physical properties, too. The magnetic susceptibility of pure Pd is reduced by both silver and hydrogen addition demonstrating the change of the electron structure. The other properties, which are impor- tant in this context, i.e. hydrogen solubility, hydrogen diffusivity, nuclear magnetic relaxation rates, also depend on the composition. NMR —as is well known— is one of the most widely applied local methods, and hydrogen nuclei serve a priori as local probes for the investigation of different microscopic properties

The paper presents the results of an experimental investigation of rigid-lattice proton magnetic resonance (PMR) spectra and second moments in Ni 0.67 Zr 0.33 –H, Ni 0.50 Zr 0.50 –H, Ni 0.33 Zr 0.67 –H binary glassy alloy–hydrogen systems in the range of hydrogen-per-metal ( H / M ) ratio of 0.14≤ H / M ≤1.9. The line shape can be described by the empirical Harper-Barnes function with exponent values ranging from 1.45 to 2.95 in the whole hydrogen concentration range. The generally assumed Gaussian form is valid in a narrow H / M interval only. The second moment as a function of H / M can be fitted by a power function of an exponent 3/4. The exponent is independent of the composition of the alloy. We found that a simple lattice gas model based on a homogeneous hydrogen distribution contradicts the experimental results. Instead, a short-range order model has been proposed in which the hydrogen atoms are located in the centres of distorted tetrahedra of metal atoms, that is in the basic building blocks of the amorphous alloys. The Switendick criterion was also taken into consideration. We have shown that few proton first neighbours (0–2) and a small number of second neighbours (1–8), that is, a cluster of hydrogen is sufficient to account for the measured value of the second moment. Ternary Zr 0.5 Ni 0.5− x Cu x –H alloys have been investigated, too. The addition of Cu nuclei did not lead to the second moment enhancement expected for a homogeneous distribution of components.

Results of electrical resistance measurements are given on Pd80 Ag20 alloy during hydrogen uptake from gaseous H2 atmosphere and from liquid electrolyte by cathodic charging. For both cases in the course of a monotonous increase of the hydrogen concentration in the alloy, the electrical resistivity shows anomalous behavior. These kinetic curves reflect the effect of phase changes in the non-equilibrium state. The ‘non-equilibrium’ expression is used in this entire work in the sense that no care was taken in waiting for the stable value of resistivity after any partial filling, but the resistivity was frequently measured while the sample was continuously charged with hydrogen. A model has been proposed for the interpretation of the experimental findings.

1H NMR spectra of the spin-crossover compound [Fe(ptz)6](BF4)2 and its zinc(II) analogue were recorded on polycrystalline samples as the function of decreasing temperature in order to study the connection of the change in the electronic state and the molecular motions present in both crystals. The temperature range for the zinc compound was 295–30 K, with a cooling rate of ∼1 K min−1, while in the case of the iron(II) compound this temperature range was 298–10 K with the same cooling rate as in the case of [Zn(ptz)6](BF4)2. The analysis of the temperature dependence of the line shape parameters and calculations of 1H second moments showed the following. The temperature of the spin transition in the iron(II) compound is 132 K on cooling. On the basis of the similarity of the temperatures at which the different molecular motions appear, the same motions are present in both compounds in the whole temperature range. The [Zn(ptz)6](BF4)2 probably goes through a structural transition between 90 and 60 K, this transition manifests in the virtual increase of the average proton–proton distance, and the sign of a similar transition is also observed in [Fe(ptz)6](BF4)2.

The hydrogen charging and discharging processes are investigated in Ni67−xCuxZr33 glassy alloys by in situ resistance measurements in order to clarify the surface and bulk contribution to the activation process. The process has been monitored by conventional DC method using a computer-controlled system, exposing the samples to hydrogen at pressure from 0.1–8.6 MPa at temperatures of 293 K and 393 K. The H-contents (H/M) were determined by weight and by pulse NMR measurements. The NMR data are obtained by the Carr–Purcell–Meiboom–Gill (CPMG) method. The charging is extremely long and the resulting H-distribution is inhomogenous during the first cycle, especially at 293 K. This fact shows the significance of the surface-activation during the H-uptake from the gas phase. The duration of the second saturation decreases significantly, and the resistance–time curves obtained: on two parallel samples are very similar. The saturation value for the normalized resistance (R/R0) remains almost the same during several cycles. Increasing the temperature of the charging (393 K), the equilibrium value of the resistance decreases. The resistance of the samples at the end of the discharging process is always higher than before charging. This indicates the partial irreversibility of the H-absorption at constant temperature. This observation is correlated with the NMR results.

1 H spin–spin relaxation time ( T 2 ) and complementary hydrogen content, PMR spectrum width and spin–lattice relaxation time ( T 1 ) have been measured in Zr y (Ni 1− x Cu x ) 1− y –H ternary amorphous alloys of different hydrogen content at 0≤ x ≤33 at.% Cu and y =33, 50 and 67 at.% Zr concentrations using Carr–Purcell–Meiboom–Gill (CPMG), solid-echo and saturation recovery pulse sequences, respectively. At high hydrogen contents the T 2 measured by the slope of the CPMG echo train depends on both the Zr and Cu content, but is independent of the hydrogen content. The differences in the spin–spin relaxation behaviours can be attributed to the substantial change of correlation time and not to the change of activation energy or local fields. The measurements were made in the “motional narrowing” state, consequently our E a and τ ∞ quantities are averaged to the diffusion motion of protons taking part in this process. At small hydrogen contents T 2 depends on hydrogen content and the T 2 vs. 1/ T curves cannot be fitted by single Arrhenius plots. The hydrogen content measured by echo train has turned out to be systematically smaller than that measured by weight increase, demonstrating that not all the hydrogen takes part in the diffusion process.

The mobility of the proton-proton radial vectors is introduced as a quantitative measure for the structural dynamics of organic materials, especially protein molecules. As defined for the entire molecule, the hydrogen mobility (HM) is proposed as an “order parameter,” which describes the effect of motional narrowing on inter-proton dipole-dipole interactions. HM satisfies all requirements of an order parameter in the Landau molecular field theory of phase transitions. The wide-line NMR second moments needed to obtain HM are exactly defined and measurable physical quantities, which are not produced by mathematical fitting and do not carry the limitations and restrictions of any model (theoretical formalism). We first demonstrate the usefulness of HM on small organic molecules with data taken form the literature. We outline its link with structural and functional characteristics on a range of proteins: HM provides a model-free parameter based on first principles that can clearly distinguish between globular and intrinsically disordered proteins, and can also provide insight into the behavior of disease-related mutants.

Proton spin–lattice relaxation times were measured between 2.2 K and room temperature in [Zn(ptz)6](BF4)2(ptz = 1-n-propyl-1H-tetrazole) and in the spin-crossover complex [Fe(ptz)6](BF4)2. Three different types of intramolecular motion of the propyl group are suggested in [Zn(ptz)6](BF4)2, namely tunneling and classical rotation of methyl groups and rotation of methylene groups. Correlation times and activation energies are calculated for tunneling rotation of the CH3group and for the classical (hindered) rotations of –CH3and –CH2–CH3as reorientations over a three-well asymmetrical potential. In [Fe(ptz)6](BF4)2the mechanism for the paramagnetic relaxation is found to be of the rapid-diffusion type according to the theory of Lowe and Tse, and the intramolecular motions are suggested to be the same as for the zinc complex.

A two-exponential spin-lattice ( T 1 ) relaxation process of hydrogen nuclear magnetization was found in a series of hydrogenated amorphous carbon samples prepared under different self-bias conditions from benzene. The temperature dependence of these relaxation times reveals the different dynamic background of the two sub-systems. Low activation energies (depending on self-bias voltages) were measured for the longer relaxation time components; temperature independence was detected for the shorter relaxation time components.

Spin-spin relaxation time ( T 2 ) and complementary hydrogen content (H/M), PMR spectrum width (FWHM) and spin lattice relaxation time ( T 1 ) have been measured in (Ni 1 − x Cu x ) 0.5 Zr 0.5 -H y ternary amorphous alloys at 0 ⩽ x ⩽ 29 at.% concentrations using Carr-Purcell-Meiboom-Gill (CPMG), solid-echo and saturation recovery pulse sequences respectively. The T 2 relaxation time measured by the slope of the CPMG echo train depends on both the hydrogen and Cu content. The dependence can be attributed to the change of correlation time and not to the change of activation energy or local field. The measurements were made in the ‘motional narrowing’ state; consequently our E a and τ ∞ quantities are averaged to the diffusional motion of protons taking part in this process. The extrapolated amplitude of the echo train measured on the alloy-hydrogen system and normalized to the same quantity in water, gives the value of proton magnetization in thermal equilibrium, that is the hydrogen content free from any perturbing effects. The hydrogen content measured by CPMG echo train has turned out to be systematically smaller than that measured by weight increase.

Equilibrium pressure and potential measurements at room temperature as a function of hydrogen concentration are reported for Ni 1− x Zr x amorphous alloys with 0.33 ⩽ x ⩽ 0.45. The full range of charge of the samples was achieved by taking into account the hydrogen gas evolved in the closed electrochemical cell. The change in slope of the equilibrium potential with the state of charge shows that different types of site are filled. On the basis of the pressure-composition (P-C) diagrams, the samples with x = 0.33, 0.36 and 0.39 were selected for further electrochemical investigations.

The proton NMR line shift with respect to water, the bulk susceptibility and in a few cases the Korringa contribution to the spin lattice relaxation time were measured in Zr0.33Ni0.67 Hx amorphous alloys with hydrogen concentration 0.1 ⩽ x ⩽ 0.7and at 343 K. All the parameters, including the hydrogen content and the bulk susceptibility, were measured simultaneously in situ, and in the shift measurements a resolution of ±1 ppm was attained. The residual Knight shift depends on the hydrogen content and is positive relative to water. Preliminary low temperature spin lattice relaxation time measurements indicate that the positive shift is the consequence of the balance of s- and d-contributions.

Proton magnetic resonance spectra of Zr 0.5 Cu y Ni 0.5−y H 1 metallic glass samples with 0 ≤ y ≤ 0.3 were measured in the temperature range 77 K to 400 K and at 8, 28.5, 87.6 and 88.5 MHz frequencies. The data of the free-induction decay (FID) signal were compiled and Fourier transformed by a SMIS NMR spectrometer. The temperature dependence of the line shapes shows three distinctly different features: (i) in the temperature range 400 K to 270 K the spectrum is a motionally narrowed Lorentzian line; (ii) in the temperature range 270 K to 140 K the spectrum consists of a narrow Lorentzian component and a substantially wider Gaussian one; (iii) in the temperature range 140 K to 77 K, the spectrum is a “two-peaked” line. The distance between the two peaks (splitting) was found to be independent of the temperature and the frequency, that means that the low-temperature spectrum is probably the Pake doublet of hydrogen pairs. From the analysis of the splitting of the Pake doublet, a proton-proton distance of 0.167 nm was estimated. This distance corresponds to a transition metal mediated hydrogen pairing.

The time evolution of the hydrogen absorption of melt-quenched Zr50Ni50 amorphous alloy ribbons was investigated for the as-quenched state and after a relaxation heat treatment. Hydriding was performed from the gas phase at 200 °C and 35 atm H2 gas pressure for charging times up to t = 48 h. The absorption process was monitored by measuring the mass increase, the thermoelectric power and the magnetization of the hydrided ribbons. For both the as-quenched and relaxed state, homogeneously hydrided ribbons could only be obtained at small ( H M ) and high ( H M ≈ 1 ) hydrogen contents. The maximum amount of absorbed hydrogen was found to be the same for both states; however, the hydrogen absorption process in the relaxed ribbons required considerably longer times than for the as-quenched state. As in our previous study of a Zr47.5Ni52.5 metallic glass, the magnetization measurements indicated also for the present alloy the occurrence of a phase separation process leading to the development of strongly magnetic nickel-rich clusters for long charging times.

The influence of hydrogen on some physical properties and on the micro-structure of a nearly equiatomic, melt-quenched NiZr amorphous alloy was investigated. Hydrogen absorption from the gas phase at 190 °C and 35–40 atm pressure was measured by weight as a function of the charging time. Considerable hydrogen absorption occurred only for charging times around 10 h and was completed within a few hours. The hydrogen content remained constant for a hydrogen-to-metal ratio of about one for prolonged charging. The room-temperature thermopower changed considerably upon hydriding and a local thermopower probe revealed that the activation time varies considerably along the ribbon length. It was found that, during further heat treatment in a hydrogen gas atmosphere after a hydrogen-to-metal ratio of approximately one was reached, the magnetic state of the amorphous NiZr samples changed progressively from paramagnetic to superparamagnetic. The density and size of the magnetic clusters, which were nickel-rich segregations induced by the hydriding process, were determined by magnetic and scanning transmission electron microscopic measurements. After desorbing hydrogen at elevated temperatures, magnetic measurements indicated the disappearance of the superparamagnetic clusters.

The proton rotating-frame spin lattice relaxation time T1r has been measured in (Ni0.5Zr0.5)0.95P0.05H0.54 and (Ni0.5Zr0.5)Po0.07H0.58 amorphous alloys in the temperature range 140–370 K. A single-exponential relaxation decay was obtained from 200 to 370 K only. The experimental data above 200 K were interpreted on the basis of a model involving diffusion of the hydrogen atoms. It is demonstrated that, by using a gaussian distribution of diffusion activation energies about a temperature independent mean energy E a = 0.32 eV atom−1 and a full width at half maximum ΔE = 0.07 eV, the temperature dependence of T1r can be well fitted in the 200–370 K range. These values are compared with relevant hydrogen diffusion data from the literature on other amorphous alloys

PMR linewidths (Δν) and spin-lattice relaxation times (T1) were measured on [M(1-n-propyl-1H-tetrazole)6](BF4)2 (M is Zn or Fe). Three motional minima of T1 associated with steps of Δν were found, and a structural change in the temperature region of 100 to 120 K is suggested in the zinc complex. The spin transition temperature was found to be ∼130 K, and an anomalous minimum of T1 occurred at 9 K in the iron complex.

Results of resistivity measurements during electrolytical hydrogen charging on some Fe, Co and Ni based alloy ribbons in amorphous, nanocrystalline and body-centred cubic state are presented. The peculiarities of the H uptake are significantly different for the different structural modifications of alloys with the same chemical composition. In the limited concentration interval of equality of the transferred charge and the number of actually absorbed hydrogen atoms, the concentration variation of the resistivity increment caused by unit hydrogen concentration was determined.

The proton content in Zr 0.33 Ni 0.67 H x amorphous alloy was monitored by changes in electrical resistivity and with the extraplated spin echo amplitude measured by the Carr-Purcell-Meiboom-Gill (CPMG) nuclear magnetic resonance pulse sequence in the temperature interval 300 to 450 K. Both methods show that the hydrogen desorption processes can be approximately divided into two ranges. The first is a fast process which is at present not interpretable. In the second stage, the process is thermally activated, and the activation energy calcualted from the resistivity changes is equal to 0.32 ± 0.04 eV. The CPMG spin echo measurements also give the spin-spin relaxation time of diffusing protons and the activation energy of this process, 0.34 ± 0.02 eV, is exactly the same as extracted from the resistivity measurements.

Results of electrical resistance measurements are given on Pd80 Ag20 alloy during hydrogen uptake from gaseous H2 atmosphere and from liquid electrolyte by cathodic charging. For both cases in the course of a monotonous increase of the hydrogen concentration in the alloy, the electrical resistivity shows anomalous behavior. These kinetic curves reflect the effect of phase changes in the non-equilibrium state. The ‘non-equilibrium’ expression is used in this entire work in the sense that no care was taken in waiting for the stable value of resistivity after any partial filling, but the resistivity was frequently measured while the sample was continuously charged with hydrogen. A model has been proposed for the interpretation of the experimental findings.

For determination of the hydrogen content in metallic samples the gravimetric method is generally used, but the large change of the electrical resistivity observed on H-absorption can also be used. The latter method is very effective if the time dependence of the process is important. The resistivity change of the sample can easily be used for monitoring the H-absorption in a gas atmosphere and with some caution for the determination of the H content in galvanic doping as well. Results are presented for the Zr33Ni67 amorphous alloy with both methods of H charging.

We studied the nuclear magnetic resonance (NMR) spin-lattice relaxation time T 1 for hydrogen in amorphous metal hydrides of the form (Ni 0.5 Zr 0.5 ) 1−x P x H y as a function of both hydrogen and phosphorus concentration. We found that the hydrogen diffusion contribution dominates T 1 over most of the temperature range from 500 K down to 150 K. The diffusion activation energy is of the order of 0.39 eV, but has a wide distribution and, in particular, low energy contributions are present which are appreciable down to the lowest temperatures studied. The Korringa relaxation time T 1e controls T 1 at the lowest temperatures and highest frequencies used. The system shows single-phase behavior above room temperature but two-phase behavior at 150 K.

Multiphase oxide superconductors of nominal compositions Tl 2 BaCa 2 Cu 3 O x have been synthesized and characterized by resistivity and magnetic susceptibility measurements. NMR spin echoes of both thallium isotopes ( 203 Tl and 205 Tl) have been detected and the line shifts, the spin-lattice and spin-spin relaxation times have been measured at room temperature for the more abundant 205 Tl nuclei. The temperature dependence of the spin-lattice relaxation rate is also reported. The results suggest that, similarly to the behavior of Y in YBa 2 Cu 3 O 7 oxides, Tl has a small electronic density of states at the Fermi level in the Tl-Ba-Ca-Cu oxide superconductors.

The electronic structure of amorphous ZrNiP and ZrNiPH alloys was studied by means of ultraviolet photoemission spectroscopy. It was established that new states were induced around 5.7 eV binding energy by hydrogen and, at the same time, the density of states (DOS) at the Fermi level decreased. The Ni peaks below the Fermi level are shifted to higher binding energies upon hydrogenation whereas the position of the Zr peak remains unchanged but its intensity is reduced due to the presence of hydrogen. The decrease of the DOS at the Fermi level indicates that H atoms interact with Zr atoms only. On the other hand, the clear shift in the Ni d-states shows that the Ni states are affected by hydrogen via changes in the ZrNi bonding.

The thermoelectric power and resistance of (Zr48.5Ni51.5)99.3P0.7-H metallic glasses were measured. The thermoelectric power decreases from S ≈ 2 μV K−1 at zero hydrogen-to-metal ratio (HM = 0) to a negative value (S ≈ −2 μV K−1) at a hydrogen-to-metal ratio of 0.7 (HM = 0.7). These results show the high sensitivity of the thermoelectric power to hydrogen concentration and are consistent with the Mott model.

A magic-angle spinning nuclear magnetic resonance (NMR) study of the Knight shift effects in rapidly quenched alloys is presented. The 31P NMR of the melt-quenched crystalline Ni3P alloy shows that the average Knight shift and the distribution of isotropic shifts are significantly different from the corresponding values for normal crystals. The results are explained as off-stoichiometry and grain size effects on the electronic structure respectively. The NMR of hydrogen in a ZrNiP-type melt-quenched amorphous alloy shows a dependence of the average Knight shift and isotropic Knight shift distribution on the hydrogen content. These results can be explained by assuming a dilatation of the metallic matrix and by specific hydrogen dynamics respectively.

Quadrupole effects in room-temperature continuous-wave (CW)63Cu nuclear magnetic resonance (NMR) spectra, “π/2” pulse length shortening and amplitudes of two-pulse generated echoes were investigated on nanocrystalline copper powders produced by cryogenic melting and by ball milling techniques. Systematic measurements on the parent polycrystalline copper and on copper-based copper-palladium dilute alloys on the basis of the same experimental techniques were also made and the results were compared to that of the nanophase samples. Fractions of Cu nuclei contributing to the specific NMR responses and average field gradients coming from noncubic neighborhoods were estimated in all the investigated cases. The satellite and/or central component origins of NMR spectra of the samples are not a priori trivial even in the simplest case. Comparative analysis of CW and pulsed experiments allowed a surprising technological conclusion to be drawn by finding a smaller chemical impurity content inside the nanograins than the value characteristic of the entire sample. The measured decrease of the impurity concentration in the inner region of the copper nanoparticles is the consequence of the applied technologies: cryogenic melting and ball milling. These preparation methods cause grain-boundary segregation and result in a cleaner inside of copper nanoparticles.

Conductance noise measurements done on point contacts of (melt-quenched) glassy metal ribbons are reported. The lower limit of the 1/f noise factor obtained was stronger by 3-5 orders of magnitude than that usual in ordinary metals. That result supports the "two potential well tunelling" model of 1/f noise in glassy metals. The conductance fluctuations measured in hydrogenized glassy metals proved to be also 1/f noise. Diffusion noise due to hydrogen has not been found.