Flux Pinning Defects Induced by Electron Irradiation in Y1Ba2Cu3O7–8 Single Crystals

1992 ◽  
Vol 275 ◽  
Author(s):  
J. Giapintzakis ◽  
M. A. Kirk ◽  
W. C. Lee ◽  
J. P. Rice ◽  
D. M. Ginsberg ◽  
...  
Keyword(s):  
Single Crystals ◽  
Electron Energy ◽  
Point Defects ◽  
Electron Irradiation ◽  
Flux Pinning ◽  
Small Clusters

ABSTRACTSingle crystals of R1Ba2Cu3O7–8, (R=Y, Eu and Gd), have been irradiated with 0.4–1.0 MeV electrons in directions near the c-axis. An incident threshold electron energy for producing flux pinning defects has been found. In-situ TME studies found no visible defects induced by electron irradiation. This means that point defects or small clusters ( ≤ 20 Å) are responsible for the extra pinning. A consistent interpretation of the data suggests that the most likely pinning defect is the displacement of a Cu atom from the CuO2 planes.

Enhanced flux pinning by Fe point defects in Bi2Sr2Ca(Cu1−xFex)2O8+δ single crystals

2000 ◽  
Vol 337 (1-4) ◽  
pp. 221-224 ◽  
Author(s):  
X.L Wang ◽  
J Horvat ◽  
G.D Gu ◽  
K.K Uprety ◽  
H.K Liu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Point Defects ◽  
Flux Pinning

Suppression of Thermal Grain Growth in Nickel by Prior Electron Irradiation

1993 ◽  
Vol 316 ◽  
Author(s):  
Yuzun Gao ◽  
Charles W. Allen ◽  
R. C. Bitrtcher
Keyword(s):  
Electron Beam ◽  
Grain Growth ◽  
Thermal Annealing ◽  
Electron Energy ◽  
Electron Irradiation ◽  
Ion Beam ◽  
In Situ Tem ◽  
Anomalous Effect ◽  
Beam Injection

ABSTRACTAn anomalous effect of electron irradiation on thermal grain growth in Ni has been observed using in situ TEM. Grain growth during thermal annealing was suppressed in areas irradiated with electrons. Grain growth suppression required a minimum electron energy between 100 and 200 keV. This alteration of thermal grain growth is attributed to electron beam injection of a surface contaminant such as carbon. This work points out that care must be exercised in the execution and evaluation of in situ TEM or ion beam experiments that deal with microstructural changes which are highly compositionally sensitive.

scholarly journals In-Situ Study of Silicon Single Crystals Conductivity under Electron Irradiation

2012 ◽  
Vol 03 (05) ◽  
pp. 383-387
Author(s):  
Hrant N. Yeritsyan ◽  
Aram A. Sahakyan ◽  
Sergey K. Nikoghosyan ◽  
Vachagan V. Harutyunyan ◽  
Karen Sh. Ohanyan ◽  
...  
Keyword(s):  
Single Crystals ◽  
Electron Irradiation ◽  
In Situ Study

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Investigation of Switching Mechanism in HfO2-Based Oxide Resistive Memories by In-Situ Transmission Electron Microscopy and Electron Energy Loss Spectroscopy

2017 ◽  
Author(s):  
T. Dewolf ◽  
D. Cooper ◽  
N. Bernier ◽  
V. Delaye ◽  
A. Grenier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Hafnium Dioxide ◽  
Switching Mechanism ◽  
Transmission Electron ◽  
Electron Energy Loss

Abstract Forming and breaking a nanometer-sized conductive area are commonly accepted as the physical phenomenon involved in the switching mechanism of oxide resistive random access memories (OxRRAM). This study investigates a state-of-the-art OxRRAM device by in-situ transmission electron microscopy (TEM). Combining high spatial resolution obtained with a very small probe scanned over the area of interest of the sample and chemical analyses with electron energy loss spectroscopy, the local chemical state of the device can be compared before and after applying an electrical bias. This in-situ approach allows simultaneous TEM observation and memory cell operation. After the in-situ forming, a filamentary migration of titanium within the dielectric hafnium dioxide layer has been evidenced. This migration may be at the origin of the conductive path responsible for the low and high resistive states of the memory.

Effect of Mn3+ doping on crystal structure, point defects, and optical properties in green Ca3(VO4)2 single crystals

2021 ◽  
pp. 111300
Author(s):  
Galina M. Kuz’micheva ◽  
Liudmila. I. Ivleva ◽  
Irina A. Kaurova ◽  
Evgeny V. Khramov ◽  
Victor B. Rybakov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Single Crystals ◽  
Point Defects
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