The effects of sulfuric acid on the creep, recrystallization, and electrical properties of ice

2003 ◽  
Vol 81 (1-2) ◽  
pp. 395-400 ◽  
Author(s):  
D Iliescu ◽  
I Baker ◽  
X Li
Keyword(s):  
Electrical Resistivity ◽  
Sulfuric Acid ◽  
Single Crystals ◽  
Equal Channel Angular Extrusion ◽  
Boundary Migration ◽  
Constant Load ◽  
Tensile Creep ◽  
Grain Boundary Migration ◽  
Resistivity Measurements ◽  
Lower Resistivity

Both constant load creep and recrystallization are investigated using single crystals of 70–170 ppb sulfuric-acid-doped and -undoped ice. Both sets of crystals exhibited strains in excess of 200% under tensile creep. The undoped specimens reached these strains roughly twice as fast as the doped specimens. After large local strains were imparted to cuboidal single crystals using equal channel angular extrusion at –2°C and subsequent annealing at the same temperature, recrystallization occurred. It was found that a higher concentration of H2SO4 retarded both recrystallization and the subsequent grain-boundary migration. Direct current electrical resistivity measurements performed on polycrystalline, sulfuric-acid-doped (3 ppm) ice at –10°C showed a much lower resistivity in the grain boundaries than in the lattice. PACS No.: 81.90

CRYSTAL GROWTH OF MULTI-LAYERED Ba2Ca4Cu5O10(O,F)2 (F-0245) SUPERCONDUCTOR UNDER HIGH PRESSURE

2005 ◽  
Vol 19 (01n03) ◽  
pp. 263-266 ◽  
Author(s):  
K. TOKIWA ◽  
H. OKUMOTO ◽  
S. KONO ◽  
S. IGA ◽  
K. TAKEMURA ◽  
...  
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
Crystal Growth ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Cuprate Superconductors ◽  
Resistivity Measurements ◽  
Starting Mixture

Single crystals of multi-layered Ba 2 Ca 4 Cu 5 O 10( O , F )2 superconductor(F-0245) have been grown under a high pressure of 4.5 GPa . Single crystals with in-plane length of 500μm were typically obtained and flat shiny areas with more than 1 mm 2 were also observed on the surface of fractured samples. Tc values for these samples were determined by electrical resistivity measurements. These values were found to change from 70 K to 85 K by change of oxygen and fluorine contents in the starting mixture. The temperature dependence of resistivity showed characteristic of under-doped cuprate superconductors.

Electrical resistivity of gallium single crystals at low temperatures

1951 ◽  
Vol 209 (1099) ◽  
pp. 542-550 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Specific Heat ◽  
Single Crystals ◽  
Low Temperatures ◽  
Room Temperature ◽  
Resistivity Measurements ◽  
Characteristic Temperatures ◽  
The Ideal

Electrical resistivity measurements on single crystals of gallium grown to conform approximately to the three axial directions have been extended to low temperatures, detailed investigation being made over the range 20.4 to 4.2° K. The anisotropy of this property increases in this region where the resistivity ratios for the three specimens are approximately 1: 2.1: 8 compared with 1: 2.1 6 : 6.5 5 at room temperature. The ‘ideal’ resistivity is proportional to T n , where n ≃ 4.45 for the range 5 to 12° K and decreases to about 3.9 for the range 12 to 20.4° K. The characteristic temperatures as derived from Grüneisen’s expression show relatively small differences for the three axial directions but decrease with decrease in temperature. Comparable variations with temperature are observed in the characteristic temperatures derived previously from specific heat measurements on gallium.

Magnetically Driven Selective Grain Growth in Locally Deformed Zn Single Crystals

2004 ◽  
Vol 467-470 ◽  
pp. 763-770 ◽  
Author(s):  
P.J. Konijnenberg ◽  
Dmitri A. Molodov ◽  
Günter Gottstein
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Grain Growth ◽  
Driving Force ◽  
Grain Orientation ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Single Temperature ◽  
Individual Grains

In magnetically anisotropic materials a driving force for grain boundary migration can be induced by an external magnetic ¯eld. It is experimentally shown that annealing of locally deformed Zn single crystals in a suitably directed high magnetic ¯eld results in a growth of new individual grains. Velocities of some solitary moving grain boundaries were measured and their absolute mobilities were estimated at a single temperature. Results are discussed in terms of preferential grain orientation and boundary character.

Observations of Orientation Dependent Creep of Ni3AI

1998 ◽  
Vol 552 ◽  
Author(s):  
Carola Knobloch ◽  
Karin Glock ◽  
Uwe Glatzel
Keyword(s):  
Single Crystals ◽  
Antiphase Boundary ◽  
Constant Load ◽  
Tensile Creep ◽  
Slip Systems ◽  
Transmission Electron ◽  
Secondary Stage ◽  
Anisotropic Elastic ◽  
Stationary Creep ◽  
Habit Planes

ABSTRACTThe influence of crystal orientation on the high temperature creep behavior of Ni3(Al Ti Ta) was investigated by tensile creep testing under a constant load at a temperature of 1123K. The single crystals were oriented close to [001], [011], [111], [557] and [012]. The results show an increasing stationary creep rate from [111] over [011] to [001]. The evolution of the microstructure during creep deformation was studied, using transmission electron microscopy (TEM). Only few systems are active in the primary regime, whereas several slip systems operate in the secondary stage. Habit planes of dislocation pairs separated by an antiphase boundary were examined and compared with anisotropic elastic calculations, explaining the good creep response of [111] oriented single crystals.

scholarly journals Coupled stress-strain and electrical resistivity measurements on copper based shape memory single crystals

2004 ◽  
Vol 7 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Cezar Henrique Gonzalez ◽  
Ney Freitas de Quadros ◽  
Carlos José de Araújo ◽  
Michel Morin ◽  
Gerard Guénin
Keyword(s):  
Electrical Resistivity ◽  
Shape Memory ◽  
Single Crystals ◽  
Stress Strain ◽  
Resistivity Measurements ◽  
Coupled Stress

Formation of Dislocations in NiAl Single Crystals Studied by In Situ Electrical Resistivity Measurement

1997 ◽  
Vol 500 ◽  
Author(s):  
Y. Q. Sun ◽  
P. M. Hazzledine ◽  
D. M. Dimiduk
Keyword(s):  
Electrical Resistivity ◽  
Single Crystals ◽  
Yield Point ◽  
Resistivity Measurement ◽  
Electrical Resistivity Measurement ◽  
Plastic Yielding ◽  
Resistivity Measurements ◽  
Density Of Dislocations ◽  
Abrupt Jump

ABSTRACTThis paper reports experiments in which in situ electrical resistivity measurements were used to monitor the formation of dislocations in initially dislocation-free NiAl single crystals. The electrical resistivity is found to exhibit an abrupt jump at the onset of plastic yielding. This is interpreted to result from an abrupt nucleation of a massive density of dislocations at the yield point.

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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