ELECTRICAL CONDUCTIVITY AND RAMAN SCATTERING OF AMORPHOUS V2O5 – LiBO2

A series of experiments of structural, vibrational and electrical transport characterization of gallium arsenide (GaAs) have been performed up to 24.3 GPa under hydrostatic conditions in a diamond anvil cell (DAC) in conjunction with in situ Raman scattering spectroscopy, electrical conductivity measurements, high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM). Upon compression, a phase transition from the zinc-blende (zb) to the orthorhombic (Cmcm) structure of GaAs was observed at 12.2 GPa through the discontinuous variations of the Raman shifts, Raman full-width at half-maximum values and electrical conductivity. Furthermore, the results of variable temperature electrical conductivity experiments confirmed that the high-pressure phase (Cmcm) exhibited one obvious metallic behavior. Upon decompression, the Raman scattering results of the recovered sample under ambient conditions indicated that the phase transition was reversible under hydrostatic conditions. The reversibility of the phase transition was further verified by HRTEM and AFM images for the recovered sample.

Download Full-text

Water Enrichment/Depletion of Amorphous Carbon Coatings Probed by Temperature-Dependent Dc Electrical Conductivity and Raman Scattering

Applied Surface Science ◽

10.1016/j.apsusc.2021.151052 ◽

2021 ◽

pp. 151052

Author(s):

Svetlana V. Saparina ◽

Alexandr I. Fishman ◽

Andrei A. Stolov ◽

Jie Li ◽

Sergey S. Kharintsev

Keyword(s):

Electrical Conductivity ◽

Raman Scattering ◽

Amorphous Carbon ◽

Temperature Dependent ◽

Carbon Coatings ◽

Dc Electrical Conductivity ◽

Amorphous Carbon Coatings

Download Full-text

Simultaneous Measurements of Electrical Resistivity and Raman Scattering from Conductive Die Attach Adhesives

MRS Proceedings ◽

10.1557/proc-682-n2.10 ◽

2001 ◽

Vol 682 ◽

Cited By ~ 1

Author(s):

Joseph Miragliotta ◽

Richard C. Benson ◽

Terry E. Phillips ◽

John A. Emerson

Keyword(s):

Electrical Conductivity ◽

Electrical Resistivity ◽

Raman Scattering ◽

Amorphous Carbon ◽

Conductive Polymer ◽

Carbon Layer ◽

Sers Spectrum ◽

Subsequent Performance ◽

Die Attach ◽

Amorphous Carbon Layer

ABSTRACTThe development of electrical conductivity in silver (Ag)-filled conductive polymer adhesives is dependent on the thermal profile of the curing process. Previous studies of polymer adhesive systems have shown that chemical reactions at the interface of the micronsized Ag filler are a key factor in determining the subsequent performance of the conductive system. In an attempt to correlate the behavior of electrical conductivity with the chemical nature of the Ag particle interface, we have simultaneously performed electrical resistivity and surface enhanced Raman scattering (SERS) measurements on a commercial conductive adhesive. At room temperature in the low conductance state (∼10−9 ohms−1), the SERS spectrum from the uncured adhesive exhibited peaks that were identified with a molecular species bound to Ag surface via the carboxylate functionality of the adsorbate. During the thermal cure processing, the SERS data showed a partial decomposition of the carboxylate species and the formation of an amorphous carbon layer at the Ag surface. A comparison of the simultaneously recorded electrical resistance and SERS data showed a strong correlation between the development of high conductance (∼ 1 ohm−1) in the adhesive and the formation of the amorphous carbon layer.

Download Full-text

Electrical conductivity and Raman scattering of amorphous V2O5LiBO2

Materials Science and Engineering B ◽

10.1016/0921-5107(92)90004-s ◽

1992 ◽

Vol 12 (4) ◽

pp. 345-349 ◽

Cited By ~ 20

Author(s):

I. Kosacki ◽

M. Massot ◽

M. Balkanski ◽

H.L. Tuller

Keyword(s):

Electrical Conductivity ◽

Raman Scattering

Download Full-text

Raman scattering and electrical conductivity in highly disordered activated carbon fibers

Journal of Materials Research ◽

10.1557/jmr.1993.0489 ◽

1993 ◽

Vol 8 (3) ◽

pp. 489-500 ◽

Cited By ~ 38

Author(s):

A.W.P. Fung ◽

A.M. Rao ◽

K. Kuriyama ◽

M.S. Dresselhaus ◽

G. Dresselhaus ◽

...

Keyword(s):

Electrical Conductivity ◽

Activated Carbon ◽

Raman Scattering ◽

Carbon Fibers ◽

Conduction Mechanism ◽

Activated Carbon Fibers ◽

Tunneling Conduction ◽

A Charge ◽

Two Peaks ◽

Variable Range Hopping Conduction

Because of their unusually large specific surface area (SSA), Activated Carbon Fibers (ACF's) have a huge density of micropores and defects. The Raman scattering technique and low-temperature dc electrical conductivity measurements were used as characterization tools to study the disorder in ACF's with SSA ranging from 1000 m2/g to 3000 m2/g. Two peaks were observed in every Raman spectrum for ACF's and they could be identified with the disorder-induced peak near ∼1360 cm−1 and the Breit–Wigner–Fano peak near ∼1610 cm−1 associated with the Raman-active E2g2 mode of graphite. The graphitic nature of the ACF's is shown by the presence of a well-defined graphitic structure with La values of 20–30 Å. We observed that the Raman scattering showed more sensitivity to the precursor materials than to the SSA of the ACF's. From 4 K to room temperature, the dc electrical resistivity in ACF's is observed to follow the exp [(T0/T)1/2] functional form and it can be accounted for by a charge-energy-limited tunneling conduction mechanism. Coulomb-gap conduction and n-dimensional (n ≤ 3) variable-range hopping conduction models were also considered but they were found to give unphysical values for their parameters.

Download Full-text