The effect of electrical conductivity on the polarization behavior of the relaxor–ferroelectric Sr0.33Ba0.67Nb2O6

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

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Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076639 ◽

1983 ◽

Vol 41 ◽

pp. 606-607

Author(s):

Klaus-Ruediger Peters ◽

Samuel A. Green

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Critical Point ◽

Metal Films ◽

High Magnification ◽

Osmium Impregnation ◽

Instrumental Resolution ◽

20 Nm ◽

Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

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Local atomic structure of relaxor ferroelectric solids studied by pulsed neutron scattering

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170505 ◽

1994 ◽

Vol 52 ◽

pp. 554-555

Author(s):

T. Egami ◽

H. D. Rosenfeld ◽

S. Teslic

Keyword(s):

Neutron Scattering ◽

Atomic Structure ◽

Argonne National Laboratory ◽

Relaxor Ferroelectrics ◽

Relaxor Ferroelectric ◽

Crystallographic Structure ◽

Chemical Inhomogeneity ◽

Distribution Analysis ◽

Ferroelectric Transition ◽

Pulsed Neutron

Relaxor ferroelectrics, such as Pb(Mg1/3Nb2/3)O3 (PMN) or (Pb·88La ·12)(Zr·65Ti·35)O3 (PLZT), show diffuse ferroelectric transition which depends upon frequency of the a.c. field. In spite of their wide use in various applications details of their atomic structure and the mechanism of relaxor ferroelectric transition are not sufficiently understood. While their crystallographic structure is cubic perovskite, ABO3, their thermal factors (apparent amplitude of thermal vibration) is quite large, suggesting local displacive disorder due to heterovalent ion mixing. Electron microscopy suggests nano-scale structural as well as chemical inhomogeneity.We have studied the atomic structure of these solids by pulsed neutron scattering using the atomic pair-distribution analysis. The measurements were made at the Intense Pulsed Neutron Source (IPNS) of Argonne National Laboratory. Pulsed neutrons are produced by a pulsed proton beam accelerated to 750 MeV hitting a uranium target at a rate of 30 Hz. Even after moderation by a liquid methane moderator high flux of epithermal neutrons with energies ranging up to few eV’s remain.

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Total Body Electrical Conductivity Measurements in the Neonate

Clinics in Perinatology ◽

10.1016/s0095-5108(18)30515-3 ◽

1991 ◽

Vol 18 (3) ◽

pp. 611-627 ◽

Cited By ~ 15

Author(s):

Marta L. Fiorotto ◽

William J. Klish

Keyword(s):

Electrical Conductivity ◽

Conductivity Measurements ◽

Total Body

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Electrical Conductivity Imparted to Liquid Air by Alpha Rays

Scientific American ◽

10.1038/scientificamerican03201915-191bsupp ◽

1915 ◽

Vol 79 (2046supp) ◽

pp. 191-191

Keyword(s):

Electrical Conductivity

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Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200161 ◽

2020 ◽

Vol 92 (1) ◽

pp. 10901

Author(s):

Saloua El Asri ◽

Hamid Ahamdane ◽

Lahoucine Hajji ◽

Mohamed El Hadri ◽

Moulay Ahmed El Idrissi Raghni ◽

...

Keyword(s):

Heat Treatment ◽

Electrical Conductivity ◽

Single Phase ◽

Sol Gel ◽

Complex Impedance ◽

Transmission Spectra ◽

Electrical Measurements ◽

Cation Type ◽

Edx Analyses ◽

The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740 °C and at 630–700 °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

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