Scanning SQUID microscopy study of electron-doped high-Tc superconductors

2005 ◽  
Vol 426-431 ◽  
pp. 202-207 ◽  
Author(s):  
K. Isawa ◽  
T. Uefuji ◽  
K. Yamada
Keyword(s):  
Microscopy Study ◽  
High Tc Superconductors ◽  
High Tc ◽  
Scanning Squid ◽  
Scanning Squid Microscopy

Local magnetic properties of high-Tc superconductors probed by scanning SQUID microscopy

2003 ◽  
Vol 388-389 ◽  
pp. 267-268
Author(s):  
Junpei Kasai ◽  
Noriaki Okazaki ◽  
Yuri Nakayama ◽  
Teruki Motohashi ◽  
Jun-ichi Shimoyama ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Tc Superconductors ◽  
High Tc ◽  
Scanning Squid ◽  
Scanning Squid Microscopy

Electron Microscopy Study of Stoichiometric and Non-Stoichiometric Titania

1997 ◽  
Vol 3 (S2) ◽  
pp. 669-670
Author(s):  
Solórzano I.G. ◽  
Kotani T. ◽  
Tuller H.L. ◽  
Van der Sande J.B.
Keyword(s):  
Electron Microscopy ◽  
Electric Activity ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Boundary Structure ◽  
High Tc Superconductors ◽  
High Tc ◽  
Grain Boundary Structure ◽  
Transmission Electron ◽  
Crystallographic Shear

It is currently well recognized that oxides are able to accommodate deviations from stoichiometry (1) and great advances in this understanding have been achieved by using transmission electron microscopy (TEM), particularly through lattice imaging and electron diffraction techniques (2). The physical properties of non-stoichiometric oxides are strongly influenced by their exact composition and for this reason they represent a class of materials with increasing and novel properties that are put to use in, for example, oxygen sensors and high-Tc superconductors. On the other hand, in electroceramic materials, such as TiO2, grain boundary structure and chemistry are important to be characterized in detail since these variables are responsible for the electric activity.Rutile (TiO2) can accommodate relatively large deviations from stoichiometry (TiOx with 2.0≥x≤ 1.75) by the crystallographic shear (CS) mechanism (1). The formation of CS planes is effectively a two-step process which involves the ordering of oxygen vacancies on a crystallographic plane and on their elimination by a shear of the lattice.

Direct observations of vortices in a high-Tc superconductor (La1-xSrx)2CuO4 by scanning SQUID microscopy

2001 ◽  
Vol 72 (S2) ◽  
pp. S263-S266 ◽  
Author(s):  
J. Kasai ◽  
N. Okazaki ◽  
Y. Togawa ◽  
T. Sasagawa ◽  
J. Shimoyama ◽  
...  
Keyword(s):  
High Tc ◽  
High Tc Superconductor ◽  
Direct Observations ◽  
Scanning Squid ◽  
Scanning Squid Microscopy

Integration of SQUID Microscopy into FA Flow

2001 ◽  
Author(s):  
Rajen Dias ◽  
Lars Skoglund ◽  
Zhiyong Wang ◽  
David Smith
Keyword(s):  
Failure Analysis ◽  
Quantum Interference ◽  
Superconducting Quantum Interference Device ◽  
High Tc ◽  
Superconducting Quantum Interference ◽  
Current Path ◽  
Scanning Squid ◽  
Silicon Device ◽  
Scanning Squid Microscopy

Abstract Scanning superconducting quantum interference device (SQUID) microscopy using high-TC SQUID sensor has been slowly gaining acceptance in the failure analysis (FA) community as a number of silicon device manufacturers are applying the tool and technique to an ever-broadening spectrum of silicon technologies for detecting the location of leakage and short failures by imaging the current path through the die and package. This paper will present the application of scanning SQUID microscopy to short isolation on die and explore the integration of this technique into the FA flow. From the examples presented in this paper, it can be seen that die level short isolation has been possible even when the separation from SQUID sensor to current is about 800-900µm. Several potentially useful techniques that will increase the accuracy of locating the die level short nondestructively are also discussed.

Observation of diamagnetic precursor to the Meissner state above Tc in high-Tc La2−xSrxCuO4 cuprates by scanning SQUID microscopy

2002 ◽  
Vol 367 (1-4) ◽  
pp. 9-14 ◽  
Author(s):  
I Iguchi ◽  
A Sugimoto ◽  
T Yamaguchi ◽  
N Chaki ◽  
T Miyake ◽  
...  
Keyword(s):  
Meissner State ◽  
High Tc ◽  
Scanning Squid ◽  
Scanning Squid Microscopy

The many faces of STEM in materials science

1991 ◽  
Vol 49 ◽  
pp. 440-441
Author(s):  
John Silcox
Keyword(s):  
Materials Science ◽  
Auger Spectroscopy ◽  
Dark Field ◽  
High Tc Superconductors ◽  
High Tc ◽  
Acoustic Environment ◽  
Electromagnetic Vibration ◽  
The Many ◽  
Serial Mode

Determination of the microstructure and microchemistry of small features often provides the insight needed for the understanding of processes in real materials. In many cases, it is not adequate to use microscopy alone. Microdiffraction and microspectroscopic information such as EELS, X-ray microprobe analysis and Auger spectroscopy can all contribute vital parts of the picture. For a number of reasons, dedicated STEM offers considerable promise as a quantitative instrument. In this paper, we review progress towards effective quantitative use of STEM with illustrations drawn from studies of high Tc superconductors, compound semiconductors and metallization of H-terminated silicon.Intrinsically, STEM is a quantitative instrument. Images are acquired directly by detectors in serial mode which is particularly convenient for digital image acquisition, control and display. The VG HB501A at Cornell has been installed in a particularly stable electromagnetic, vibration and acoustic environment. Care has been paid to achieving UHV conditions (i.e., 10-10 Torr). Finally, it has been interfaced with a VAX 3200 work station by Kirkland. This permits, for example, the acquisition of bright field (or energy loss) images and dark field images simultaneously as quantitative arrays in perfect registration.

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

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