Structure Characterization of Metamict and Glassy Lead Phosphates

1992 ◽  
Vol 279 ◽  
Author(s):  
A. N. Sreeram ◽  
L. W. Hobbs
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Distribution Functions ◽  
Phosphate Glasses ◽  
Structure Characterization ◽  
Optical Diffraction ◽  
Damage Layer ◽  
Significant Difference ◽  
Ion Implanted

ABSTRACTSingle crystals of Pb2P2O7 (beam stable under 200 kV TEM electrons to a fluence > 1027 e/m2 and an ionizing dose > 1014 Gy) were rendered metamict (amorphized) with ion-implantation (100 kV P+ ions with several fluences. Pb2P2O7 and PbO·P2O5 glasses were also ion implanted at identical fluences. Radial distribution functions of metamict and glassy phosphates are being generated using energy filtered electron diffraction (EFED) data collected on 100 kV field emission STEM (VG HB-5). Ion-implanted lead phosphate glasses exhibit a significant difference in their FSDP as compared to the non-irradiated ones. XTEM results also show that ion-beam damage layer was around 200 nm deep. XTEM-HREM structure images of ion-implanted single crystals, along with their optical diffraction analysis will be presented and briefly discussed.

Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Pressure Control ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Analysis ◽  
Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

Determination of Structure, Shape and Sizes of Clusters Using Radial Distribution Functions (RDF) Method

1992 ◽  
Vol 272 ◽  
Author(s):  
Pavel E. Kolosov ◽  
A. V. Bubnov
Keyword(s):  
Distribution Functions ◽  
Structure Characterization ◽  
Radial Distribution Functions ◽  
Experimental Conditions ◽  
Interatomic Distances ◽  
X Ray ◽  
Molybdenum Sulfides ◽  
X Ray Scattering

ABSTRACTThe theoretical reduced intensity of X-ray scattering i(S) may be calculated for a cluster of any structure using Debye's formula. The comparison of both experimental determination and model calculation of the RDF or i(S) allows, to make a conclusions about structure of materials in a wide region of interatomic distances. This is a very important for direct structure characterization of giant clusters, dispersed molybdenum sulfides etc.. The simple formula for the upper limit of interatomic distances when the data are collected at equidistant step on S – scatterinrg vector, may be used for the optimal experimental conditions selection.

Characterization of metamict and glassy phosphates using energy-filtered electron diffraction

1992 ◽  
Vol 50 (2) ◽  
pp. 1274-1275
Author(s):  
A. N. Sreeram ◽  
L. C. Qin ◽  
A. J. Garratt-Reed ◽  
L. W. Hobbs
Keyword(s):  
Electron Diffraction ◽  
Single Crystals ◽  
High Performance ◽  
Three Dimensional ◽  
Distribution Functions ◽  
Phosphate Glasses ◽  
Electron Diffraction Data ◽  
X Ray Diffraction ◽  
Condensed Phosphates ◽  
Lead Pyrophosphate

Lead phosphate glasses have been investigated for decades with respect to fundamental glass properties such as glass transition, devitrification, electrical and optical properties. In these glasses, [PO4] tetrahedra, (like [SiO4] tetrahedra in silicates) can link up together by corner sharing oxygen atoms to form polymerized structures upto and including three dimensional glassy networks. Although, little electron diffraction data on amorphous phosphates is available, radial distribution functions have been generated for lime phosphate glasses and amorphous aluminum phosphates using x-ray diffraction techniques. More recently, Sales et al. have examined near surfaces of single crystals of lead pyrophosphate (Pb2P2O7), rendered aperiodic (metamict) by ion implantation, and lead pyrophosphate glass using high-performance liquid chromatography (HPLC), making use of the fact that condensed phosphates do not alter their state of polymerization when dissolved in aqueous solutions.In our studies, single crystals of Pb2P2O7 were found to be beam stable under 200 keV TEM electrons to an electron fluence > 1027 e/m2 and an ionizing dose > 1014 Gy. This negative radiolytic result leaves ballistic displacement by ions or neutrons as the only route to render the samples metamict.

FIB-TEM Characterization of Locally Restricted Implantation Damage

2002 ◽  
Vol 738 ◽  
Author(s):  
Heinz D. Wanzenboeck ◽  
Stefan Harasek ◽  
Wolfgang Brezna ◽  
Alois Lugstein ◽  
Helmut Langfischer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Defect Analysis ◽  
Multilayered Structures ◽  
Damage Layer ◽  
Implantation Damage ◽  
Transmission Electron ◽  
High Resolution Tem

ABSTRACTImaging critical features by using transmission electron microscopy (TEM) or scanning electron microscopy (SEM) provides a versatile approach for nanostructure characterization. The combination of focused ion beam (FIB) technology for exposing defective sites beneath the surface is shown. Reliability testing and defect analysis by localized characterization of multilayered structures is demonstrated. TEM-imaging of a transistor gate with a locally confined radiation damage demonstrates target preparation by FIB yielding high-resolution TEM samples. The TEM imaging requires a longer sample preparation but provides high image quality (TEM). Investigation of materials previously processed with FIB revealed amorphization damage by the high energetic Ga-ion beam. This damage layer with a thickness in the range of 50 to 100 nm was confirmed in simulation. This disadvantageous damage by amorphization originating from FIB preparation of the cross-section could be removed by soft sputtering with a 250 V Ar+ ion beam. This combined method using FIB for microsample preparation and TEM for imaging and analysis was proven to be a powerful tool the exploitation of nanostructured devices and for defect analysis on a highly localized scale.

Electrical and optical characterization of ion-implanted CuGaSe2 single crystals

1998 ◽  
Vol 84 (3) ◽  
pp. 1274-1278 ◽  
Author(s):  
J. H. Schön ◽  
E. Arushanov ◽  
L. L. Kulyuk ◽  
A. Micu ◽  
D. Shaban ◽  
...  
Keyword(s):  
Single Crystals ◽  
Optical Characterization ◽  
Ion Implanted

Ion beam characterization of the ion implanted arsenic tail in silicon

1990 ◽  
Vol 47 (1) ◽  
pp. 29-32
Author(s):  
S.E. Beck ◽  
R.J. Jaccodine ◽  
A.J. Filo ◽  
F.A. Stevie ◽  
R.B. Irwin ◽  
...  
Keyword(s):  
Ion Beam ◽  
Beam Characterization ◽  
Ion Implanted
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