scholarly journals Hydrogen Absorption in Pd–Ag Systems: A TPD and Electrical Resistivity Study

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3160 ◽  
Author(s):  
Alfonso Pozio ◽  
Zoran Jovanovic ◽  
Silvano Tosti
Keyword(s):  
Electrical Resistivity ◽  
Thin Foil ◽  
Hydrogen Desorption ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
Octahedral Sites ◽  
Tetrahedral Sites ◽  
Hydrogen Retention ◽  
Temperature Programmed ◽  
Electrical Resistivity Study

Hydrogen retention in Pd–Ag (silver 21 wt. %) thin foil has been tested by means of temperature-programmed desorption (TPD) in the temperature range 25–200 °C and compared to the resistivity measurements for the purpose of explaining the characteristic S-shaped resistivity curve and its minimum observed in the same temperature range. The TPD results indicated that the highest uptake of hydrogen was between 65 °C and 105 °C, with a maximum at ~85 °C. Furthermore, in all examined cases, the hydrogen desorption peak was between 140 °C and 180 °C. The resistivity measurements in argon, hydrogen, and vacuum allowed us to examine the influence of hydrogen on the resistivity of a Pd–Ag alloy. The results showed evidence of two kinds of hydrides: (1) a weak absorption at low temperature (T < 70 °C) with the hydrogen present mainly in tetrahedral sites, and (2) a strong absorption up to 150 °C with the hydrogen present mainly in octahedral sites. The behaviour of the electrical resistivity and the minimum between 90 °C and 110 °C can be explained by the two kinds of hydrogen uploaded into the metal lattice.

EMPIRICAL ESTIMATES OF PHYSICAL PARAMETERS FROM ELECTRICAL RESISTIVITY MEASUREMENTS ON FERRITES

1996 ◽  
Vol 10 (07) ◽  
pp. 299-303
Author(s):  
MISBAH UL ISLAM ◽  
M. SHAKEEL BILAL ◽  
T. ABBAS ◽  
M.U. RANA ◽  
S. MOHSIN RAZA
Keyword(s):  
Electrical Resistivity ◽  
High Temperatures ◽  
Zinc Concentration ◽  
Physical Parameters ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
Octahedral Sites ◽  
Empirical Estimates ◽  
High Zinc ◽  
High Zinc Concentration

Measurements on the electrical resistivity of Mn 1−x Zn x Fe 2 O 4 ferrites with 0<x< 0.15 in the temperature range 300 K <T<450 K , have been carried out. Analysis of the normalised electrical resistivity of these ferrites shows deviations from linearity both at low and high temperatures. There exists a deviation in the electrical resistivity at 300 K at high zinc concentration which may be due to hopping of electrons between Fe +2 and Fe +3 ions at octahedral sites.

WEAK-LOCALIZATION EFFECT IN SINGLE CRYSTAL TaN(001) FILMS

2002 ◽  
Vol 16 (28n29) ◽  
pp. 1143-1149 ◽  
Author(s):  
ASHUTOSH TIWARI ◽  
H. WANG ◽  
D. KUMAR ◽  
J. NARAYAN
Keyword(s):  
Electrical Resistivity ◽  
Weak Localization ◽  
Negative Temperature ◽  
Careful Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
3D Localization ◽  
Temperature Coefficient Of Resistivity

We here report the manifestation of weak localization effects in the electrical resistivity of TaN (001) films grown on MgO (001) substrates by a pulsed laser deposition technique. These films were characterized by X-ray diffraction and Rutherford backscattering. High precision electrical resistivity measurements were performed on these films in the temperature range 12–300 K. A careful analysis of data showed these films to lie in the weakly localized regime with negative temperature coefficient of resistivity throughout the whole temperature range of study. A crossover from 2D localization at lower temperatures to 3D localization at higher temperatures was observed.

ELECTRICAL RESISTIVITY OF LIQUID-QUENCHED AMORPHOUS ALLOYS

1995 ◽  
Vol 09 (03n04) ◽  
pp. 195-200 ◽  
Author(s):  
S. M. M. R. NAQVI ◽  
S. DABIR H. RIZVI ◽  
S. MOHSIN RAZA ◽  
MUSHTAQ AHMAD GORMANI ◽  
N. FAROOQUI
Keyword(s):  
Electrical Resistivity ◽  
Amorphous Alloys ◽  
Empirical Relationship ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
Resistivity Data ◽  
Ferromagnetic Domains

Electrical resistivity measurements of amorphous ( Fe x Co 100-x)83 B 17 alloys in the temperature range 40 K < T < 300 K have been obtained. We observed from the analysis of the resistivity data that there is no s-d interaction or Js-d coupling. An empirical relationship for estimating Θ D is suggested from the normalized electrical resistivity data, which holds good both for theoretical and estimated Θ D . For s-d interaction or Js-d coupling to occur in ferromagnetic amorphous alloys, ordering of ferromagnetic domains, i.e. Heisenberg interaction in a disordered matrix, would require temperatures of T ≤ Θ D /50 ≃ 0.02 Θ D .

High Pressure Electrical Resistivity Study of Sm0.85Nd0.15Se

1997 ◽  
Vol 11 (26n27) ◽  
pp. 1189-1192 ◽  
Author(s):  
S. Ariponnammal ◽  
S. Natarajan
Keyword(s):  
Electrical Resistivity ◽  
Rare Earth ◽  
Lattice Parameter ◽  
Parameter Study ◽  
Rare Earth Ion ◽  
Resistivity Measurements ◽  
Divalent State ◽  
Trivalent State ◽  
Trivalent Rare Earth ◽  
Electrical Resistivity Study

The study of rare-earth monochalcogenides have received much attention because of their interesting electrical properties. They crystallize in the NaCl type structure and are semiconducting if the rare earth ion is in the divalent state and metalic if trivalent state. The effect of substitution of trivalent rare earth ion in divalent rare earth has been studied. We present the results of electrical resistivity measurements and lattice parameter study on Sm0.85Nd0.15Se . The structure of the sample is confirmed by the theoretical calculation of X-ray intensities using Lazy-Pulverix programme. The electrical resistivity is found to be decreasing with the increase of pressure.

HIGH PRESSURE ELECTRICAL RESISTIVITY STUDY ON ORTHORHOMBIC SnTe1−xSx

1996 ◽  
Vol 10 (10) ◽  
pp. 459-465
Author(s):  
S. ARIPONNAMMAL ◽  
S. NATARAJAN
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
Lattice Parameter ◽  
Layered Material ◽  
Parameter Study ◽  
X Ray ◽  
Resistivity Measurements ◽  
Resistivity Study ◽  
Sulphur Concentration ◽  
Electrical Resistivity Study

Electrical resistivity measurements under pressure and lattice parameter study on SnTe 1–xSx(0.5≤x≤1) are reported here. The structure of these samples is confirmed by the theoretical calculation of X ray intensities using Lazy-Pulverix programme. The electrical resistivity decreases with the increase of pressure and also with the decrease of sulphur concentration. High pressure electrical resistivity study has produced more evidence that the compounds are layered material.

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

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