Influence of crystal defects on the irreversibility line of YBa2Cu3O7-x single crystals

1991 ◽  
Vol 84 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Ch. Neumann ◽  
Ch. Heinzel ◽  
P. Ziemann ◽  
K. Fischer ◽  
W. Gawalek
Keyword(s):  
Single Crystals ◽  
Crystal Defects ◽  
Irreversibility Line

Electron microscopy investigations on the mineral lorándite (TlAsS2) from Allchar in Macedonia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tobias Necke ◽  
Maximilian Trapp ◽  
Stefan Lauterbach ◽  
Georg Amthauer ◽  
Hans-Joachim Kleebe
Keyword(s):  
Electron Microscopy ◽  
Single Crystals ◽  
Secondary Phase ◽  
Lattice Energy ◽  
Local Deformation ◽  
Crystal Defects ◽  
Coffee Bean ◽  
Electron Dose ◽  
Chemical Difference ◽  
Natural Mineral

Abstract In this paper, we report on electron microscopy studies of single crystals of the natural mineral lorándite, TlAsS2. The main focus of this investigation was to address the question as to whether those lorándite crystals are chemically and structurally homogeneous, in order to be utilized as an effective neutrino detector within the lorándite experiment (LOREX) project. Apart from few secondary minerals, being present only at the surface of the lorándite samples, scanning electron microscopy (SEM) indicated homogeneous crystals. Similarly, transmission electron microscopy (TEM) imaging revealed a homogenous and undisturbed crystal structure, with the only exception of local coffee-bean contrasts; however, rarely observed. These specific contrast variations are known to be a typical strain indicator caused by a local deformation of the crystal lattice. Energy-dispersive X-ray spectroscopy (EDS) in conjunction with electron energy-loss spectroscopy (EELS) did not show any significant chemical difference when analysing regions on or off those coffee-bean features, indicating a chemically homogenous mineral. Since the presence of lattice disturbing secondary phase precipitates could be excluded by imaging and complementary chemical analysis, crystal defects such as dislocations and stacking faults or minor fluid inclusions are discussed as the probable origin of this local elastic strain. The experimental results confirm that the studied lorándite single crystals fulfil all structural and chemical requirements to be employed as the natural mineral that allows to determine solar neutrino fluxes. In addition, critical issues regarding the rather challenging sample preparation of lorándite are reported and a quantification of the maximum tolerable electron dose in the TEM is presented, since lorándite was found to be sensitive with respect to electron beam irradiation. Furthermore, the limits of EDS measurements due to peak overlapping are shown and discussed utilizing the case of Pb in lorándite. In this regard, a comparison with the Tl- and Pb-containing natural mineral hutchinsonite, TlPbAs5S9, is also included.

Irreversibility line and second peak in the magnetization curves of Pb2Sr2Y1−xCaxCu3O8 single crystals

1996 ◽  
Vol 263 (1-4) ◽  
pp. 442-445 ◽  
Author(s):  
T. Noji ◽  
T. Takabayashi ◽  
T. Nishizaki ◽  
N. Kobayashi ◽  
Y. Koike
Keyword(s):  
Single Crystals ◽  
Irreversibility Line ◽  
Magnetization Curves ◽  
Second Peak

Influence of lead substitution on the magnetic irreversibility line of 2212 superconducting single crystals

1994 ◽  
Vol 223 (3-4) ◽  
pp. 259-266 ◽  
Author(s):  
R. Bouzerar ◽  
B. Mettout ◽  
H. Savary ◽  
J. Schneck ◽  
J.C. Tolédano
Keyword(s):  
Single Crystals ◽  
Irreversibility Line ◽  
Magnetic Irreversibility

Hysteresis loop, irreversibility line and flux creep studies in TlBa2Ca3Cu4O11−δ single crystals

1996 ◽  
Vol 268 (3-4) ◽  
pp. 287-294 ◽  
Author(s):  
Lu Zhang ◽  
J.Z. Liu ◽  
C. Hoellwarth ◽  
S.H. Irons ◽  
R.N. Shelton ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Single Crystals ◽  
Irreversibility Line ◽  
Flux Creep

Bose-glass versus surface barrier crossover in the irreversibility line of Bi2Sr2CaCu2O8 single crystals

1994 ◽  
Vol 235-240 ◽  
pp. 2813-2814 ◽  
Author(s):  
C.J. van der Beek ◽  
B. Schmidt ◽  
M. Konczykowski ◽  
V.M. Vinokur ◽  
G.W. Crabtree
Keyword(s):  
Single Crystals ◽  
Irreversibility Line ◽  
Surface Barrier ◽  
Bose Glass

Electric Field Induced De-channeling in LiNbO3

1993 ◽  
Vol 316 ◽  
Author(s):  
R. L. Zimmerman ◽  
D. Ila ◽  
N. Kukhtarev ◽  
E. K. Williams
Keyword(s):  
Electric Field ◽  
Single Crystals ◽  
Ion Beam ◽  
Crystal Defects ◽  
Alpha Particles ◽  
Fringe Field ◽  
Beam Direction ◽  
Ion Channeling ◽  
Piezoelectric Strain ◽  
Mev Protons

ABSTRACTAn electric field has been imposed on single crystals of pure and doped LiNbO3 during bombardment with 1.03 MeV protons and 2.1 MeV alpha particles. Simultaneous (p,p), (p,α) and (p,p'γ) channeling between the crystal planes showed that the channeling is less pronounced when an electric field of 106 volts/m is imposed perpendicular to the incident ion beam direction and to the channeling planes in the crystal. The results obtained are discussed and compared to the effects due to the fringe field outside the crystal, differential cation-anion movement, movement of interplanar impurities, the piezoelectric strain and movement or creation of crystal defects on ion channeling.

Relative Helicity and Jog Densities in Continuum Descriptions of Dislocations

MRS Advances ◽  
2016 ◽  
Vol 1 (25) ◽  
pp. 1847-1852 ◽  
Author(s):  
Thomas Hochrainer
Keyword(s):  
Single Crystals ◽  
Crystal Defects ◽  
Slip Systems ◽  
Dislocation Theory ◽  
View Point ◽  
Current Contribution ◽  
Topological Measure

ABSTRACTDislocations are line like crystal defects mediating plasticity in single crystals. In the current contribution we review classical continuum concepts of dislocation theory from a topological view point. Subsequently, we introduce a new measure for the density of jogs mutually impaired on each other by dislocations on different slip systems. This jog density is closely related to a topological measure of the interlinkage of the dislocations on the involved slip systems, known as relative helicity in other branches of physics.

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