Spatially resolved electronic structure of an isovalent nitrogen center in GaAs

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

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Electronic structure in confined volumes using spatially resolved electron energy loss scattering

Materials Science and Engineering B ◽

10.1016/0921-5107(92)90312-w ◽

1992 ◽

Vol 14 (3) ◽

pp. 297-303 ◽

Cited By ~ 5

Author(s):

P.E. Batson

Keyword(s):

Electronic Structure ◽

Energy Loss ◽

Electron Energy ◽

Spatially Resolved ◽

Electron Energy Loss

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Local Electronic Structure in Ordered Aggregates of Carbon Nanotubes: Scanning Tunneling Microscopy/scanning Tunneling Spectroscopy Study

Journal of Materials Research ◽

10.1557/jmr.1998.0332 ◽

1998 ◽

Vol 13 (9) ◽

pp. 2389-2395 ◽

Cited By ~ 9

Author(s):

D. L. Carroll ◽

P. M. Ajayan ◽

S. Curran

Keyword(s):

Carbon Nanotubes ◽

Electronic Structure ◽

Scanning Tunneling Microscopy ◽

Local Density ◽

Scanning Tunneling Spectroscopy ◽

Tunneling Spectroscopy ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Spatially Resolved ◽

Local Electronic Structure

The recent application of tunneling probes in electronic structure studies of carbon nanotubes has proven both powerful and challenging. Using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), local electronic properties in ordered aggregates of carbon nanotubes (multiwalled nanotubes and ropes of single walled nanotubes) have been probed. In this report, we present evidence for interlayer (concentric tube) interactions in multiwalled tubes and tube-tube interactions in singlewalled nanotube ropes. The spatially resolved, local electronic structure, as determined by the local density of electronic states, is shown to clearly reflect tube-tube interactions in both of these aggregate forms.

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Combined analysis of spatially resolved electronic structure and composition on a cross-section of a thin film Cu(In1-x Ga x )S2 solar cell

physica status solidi (a) ◽

10.1002/pssa.200881216 ◽

2009 ◽

Vol 206 (5) ◽

pp. 1017-1020 ◽

Cited By ~ 21

Author(s):

R. Mainz ◽

F. Streicher ◽

D. Abou-Ras ◽

S. Sadewasser ◽

R. Klenk ◽

...

Keyword(s):

Thin Film ◽

Electronic Structure ◽

Solar Cell ◽

Cross Section ◽

Combined Analysis ◽

Spatially Resolved

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Layer speciation and electronic structure investigation of freestanding hexagonal boron nitride nanosheets

Nanoscale ◽

10.1039/c4nr04445b ◽

2015 ◽

Vol 7 (5) ◽

pp. 1718-1724 ◽

Cited By ~ 12

Author(s):

Jian Wang ◽

Zhiqiang Wang ◽

Hyunjin Cho ◽

Myung Jong Kim ◽

T. K. Sham ◽

...

Keyword(s):

Electronic Structure ◽

Boron Nitride ◽

Hexagonal Boron Nitride ◽

Polarization Dependence ◽

Xanes Spectroscopy ◽

Structure Investigation ◽

Boron Nitride Nanosheets ◽

Spatially Resolved

Layer speciation, spatially-resolved XANES spectroscopy and polarization dependence of single and multilayered hBN nanosheets have been investigated by STXM.

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Local Electronic Structure Of Defects In Gan From Spatially Resolved Electron Energy-Loss Spectroscopy

MRS Proceedings ◽

10.1557/proc-482-763 ◽

1997 ◽

Vol 482 ◽

Cited By ~ 3

Author(s):

M. K. H. Natusch ◽

G. A. Botton ◽

R. F. Broom ◽

P. D. Brown ◽

D. M. Tricker ◽

...

Keyword(s):

Optical Properties ◽

Electronic Structure ◽

Energy Loss ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Crystal Defects ◽

Vacuum Field ◽

Spatially Resolved ◽

Local Electronic Structure ◽

Electron Energy Loss

AbstractThe optical properties and their modification by crystal defects of wurtzite GaN are investigated using spatially resolved electron energy-loss spectroscopy (EELS) in a dedicated ultra-high vacuum field emission gun scanning transmission electron microscope. The calculated density of states of the bulk crystal reproduces well the features of the measured spectra. The profound effect of a prismatic stacking fault on the local electronic structure is shown by the spatial variation of the optical properties derived from low-loss spectra. It is found that a defect state at the fault appears to bind 1.5 electrons per atom.

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Research Update: Spatially resolved mapping of electronic structure on atomic level by multivariate statistical analysis

APL Materials ◽

10.1063/1.4902996 ◽

2014 ◽

Vol 2 (12) ◽

pp. 120701 ◽

Cited By ~ 9

Author(s):

Alex Belianinov ◽

Panchapakesan Ganesh ◽

Wenzhi Lin ◽

Brian C. Sales ◽

Athena S. Sefat ◽

...

Keyword(s):

Electronic Structure ◽

Statistical Analysis ◽

Multivariate Statistical Analysis ◽

Atomic Level ◽

Multivariate Statistical ◽

Spatially Resolved

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Spatially resolved local electronic structure on graphite surface: a scanning tunneling spectroscopy investigation

Surface Science Letters ◽

10.1016/0167-2584(93)90224-7 ◽

1993 ◽

Vol 293 (3) ◽

pp. L871-L875

Author(s):

Nan Li ◽

Sishen Xie

Keyword(s):

Electronic Structure ◽

Scanning Tunneling Spectroscopy ◽

Tunneling Spectroscopy ◽

Graphite Surface ◽

Scanning Tunneling ◽

Spatially Resolved ◽

Local Electronic Structure

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Experimental Measurement of the Local Electronic Structure of Grain Boundaries in Ni3Al

MRS Proceedings ◽

10.1557/proc-319-299 ◽

1993 ◽

Vol 319 ◽

Cited By ~ 7

Author(s):

D.A. Muller ◽

P.E. Batson ◽

S. Subramanian ◽

S. L. Sass ◽

J. Silcox

Keyword(s):

Electronic Structure ◽

Grain Boundary ◽

Grain Boundaries ◽

Bulk Material ◽

Local Strain ◽

Dark Field ◽

Hole Density ◽

Spatially Resolved ◽

Boron Segregation ◽

Annular Dark Field

AbstractWe have examined grain boundaries in both undoped and boron doped Ni0.76Al0.24 using electron energy loss spectroscopy (EELS), x-ray fluorescence (EDX) and annular dark field (ADF) imaging in a UHV STEM. A detailed study of a high angle grain boundary in nickel rich Ni3Al doped with 1000 ppm boron shows nickel enrichment occurring in a 5Å wide region. Boron segregation to the boundary is observed with EELS and is seen to vary along the boundary, coinciding with ADF contrast changes in the surrounding grains that may be due to local strain fields. Spatially resolved EELS of the Ni L2,3 core edge, which is sensitive to changes in the hole density in the nickel d band, shows boron rich regions of the grain boundary to have a bonding similar to that of the bulk material. Boundary regions without boron have an electronic structure similar to that of the undoped grain boundaries where the Fermi level lies deeper in the nickel d band. In addition to studying boron segregation, EELS provides a unique opportunity to examine the changes in bonding that control the local properties of the material.

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