Determination of the Physical Properties of Oil Sands Components using Scanning Probe Microscopy

2015 ◽  
Vol 1754 ◽  
pp. 69-74
Author(s):  
Ravi Gaikwad ◽  
Tinu Abraham ◽  
Aharnish Hande ◽  
Fatemeh Bakhtiari ◽  
Siddhartha Das ◽  
...  
Keyword(s):  
Oil Sands ◽  
Structural Changes ◽  
Rational Approach ◽  
Kelvin Probe ◽  
Scanning Calorimetry ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTAtomic force microscopy is employed to study the structural changes in the morphology and physical characteristics of asphaltene aggregates as a function of temperature. The exotic fractal structure obtained by evaporation-driven asphaltene aggregates shows an interesting dynamics for a large range of temperatures from 25°C to 80°C. The changes in the topography, surface potential and adhesion are unnoticeable until 70°C. However, a significant change in the dynamics and material properties is displayed in the range of 70°C - 80°C, during which the aspahltene aggregates acquire ‘liquid-like’ mobility and fuse together. This behaviour is attributed to the transition from the pure amorphous phase to a crystalline liquid phase which occurs at approximately 70°C as shown by using Differential Scanning Calorimetry (DSC). Additionally, the charged nature of asphaltenes and bitumen is also explored using kelvin probe microscopy. Such observations can lead to the development of a rational approach to the fundamental understanding of asphaltene aggregation dynamics and may help in devising novel techniques for the handling and separation of asphaltene aggregates using dielectrophoretic methods.

Characterization of GaN and Al0.35Ga0.65N/GaN Heterostructures by Scanning Kelvin Probe Microscopy

2001 ◽  
Vol 680 ◽  
Author(s):  
G. Koley ◽  
M. G. Spencer
Keyword(s):  
Chemical Vapor ◽  
Kelvin Probe ◽  
Contact Mode ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Kelvin Probe ◽  
Gan Heterostructure ◽  
Growth Features

ABSTRACTScanning Kelvin probe microscopy (SKPM) technique operated in feedback mode has been used to characterize GaN (unintentionally n-type doped, n+ doped and semi-insulating), and Al0.35Ga0.65N/GaN heterostructures (with varying Al0.35Ga0.65N thickness) grown by metalorganic chemical vapor deposition and molecular beam epitaxy. SKPM was used to measure the surface potential on these materials. The measurement technique was calibrated using metal calibration samples of Pt, Au, Ni and Al. The BSBH for n-doped GaN was measured to be 0.7 eV, which is in good agreement with values reported in the literature. Growth features such as dislocations present on the surfaces of III-nitrides were also investigated for their electrical properties using SKPM and non-contact mode atomic force microscopy, simultaneously. The dislocations have been found to be negatively charged for GaN as well as Al0.35Ga0.65N/GaN heterostructure samples.

High-sensitivity quantitative Kelvin probe microscopy by noncontact ultra-high-vacuum atomic force microscopy

1999 ◽  
Vol 75 (2) ◽  
pp. 286-288 ◽  
Author(s):  
Ch. Sommerhalter ◽  
Th. W. Matthes ◽  
Th. Glatzel ◽  
A. Jäger-Waldau ◽  
M. Ch. Lux-Steiner
Keyword(s):  
Atomic Force Microscopy ◽  
High Vacuum ◽  
High Sensitivity ◽  
Ultra High Vacuum ◽  
Kelvin Probe ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

2018 ◽  
Vol 9 ◽  
pp. 963-974 ◽  
Author(s):  
Karolline A S Araujo ◽  
Luiz A Cury ◽  
Matheus J S Matos ◽  
Thales F D Fernandes ◽  
Luiz G Cançado ◽  
...  
Keyword(s):  
Hybrid System ◽  
Organic Semiconductor ◽  
Optical Emission ◽  
Optical Excitation ◽  
Kelvin Probe ◽  
Self Assembled Monolayer ◽  
Semiconductor Interface ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy

The influence of graphene and retinoic acid (RA) – a π-conjugated organic semiconductor – interface on their hybrid system is investigated. The physical properties of the interface are assessed via scanning probe microscopy, optical spectroscopy (photoluminescence and Raman) and ab initio calculations. The graphene/RA interaction induces the formation of a well-organized π-conjugated self-assembled monolayer (SAM) at the interface. Such structural organization leads to the high optical emission efficiency of the RA SAM, even at room temperature. Additionally, photo-assisted electrical force microscopy, photo-assisted scanning Kelvin probe microscopy and Raman spectroscopy indicate a RA-induced graphene doping and photo-charge generation. Finally, the optical excitation of the RA monolayer generates surface potential changes on the hybrid system. In summary, interface-induced organized structures atop 2D materials may have an important impact on both design and operation of π-conjugated nanomaterial-based hybrid systems.

scholarly journals Investigation of the dynamic properties of on-chip coupled piezo/photodiodes by time-resolved atomic force and Kelvin probe microscopy

AIP Advances ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 105121
Author(s):  
Willemijn M. Luiten ◽  
Verena M. van der Werf ◽  
Noureen Raza ◽  
Rebecca Saive
Keyword(s):  
Dynamic Properties ◽  
Kelvin Probe ◽  
Time Resolved ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Atomic Force ◽  
On Chip

Distinguishing negatively-charged and highly conductive dislocations in gallium nitride using scanning Kelvin probe and conductive atomic force microscopy

2002 ◽  
Vol 743 ◽  
Author(s):  
Blake S. Simpkins ◽  
Edward T. Yu ◽  
Patrick Waltereit ◽  
James S. Speck
Keyword(s):  
Atomic Force Microscopy ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Spatially Correlated ◽  
Atomic Force ◽  
Scanning Kelvin Probe ◽  
Dislocation Type ◽  
Distinct Features

ABSTRACTScanning Kelvin probe microscopy (SKPM) and conductive atomic force microscopy (C-AFM) are used to image surfaces of GaN grown by molecular beam epitaxy (MBE). Numerical simulations are used to assist in the interpretation of SKPM images. Detailed analysis of the same area using both techniques allows imaging of surface potential variations arising from the presence of negatively charged dislocations and dislocation-related current leakage paths. Correlations between the charge state of dislocations, conductivity of leakage current paths, and possibly dislocation type can thereby be established. Approximately 25% of the leakage paths appear to be spatially correlated with negatively charged dislocation features. This is approximately the level of correlation expected due to spatial overlap of randomly distributed, distinct features of the size observed, suggesting that the negatively charged dislocations are distinct from those responsible for localized leakage paths found in GaN. The effects of charged dislocation networks on the local potential profile is modeled and discussed.

scholarly journals Atomic Force Microscopy and Scanning Tunneling Microscopy of Aluminum Nanoislands

Nano Hybrids ◽  
2012 ◽  
Vol 2 ◽  
pp. 13-24 ◽  
Author(s):  
S.G. Nedilko ◽  
V. Prorok ◽  
Stanislav Rozouvan
Keyword(s):  
Scanning Tunneling ◽  
Kelvin Probe ◽  
Tunneling Microscopy ◽  
Surface Scanning ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Microscopy Technique ◽  
Atomic Force ◽  
Scanning Tunnelling ◽  
Tunnelling Microscopy

Aluminum nanoislands deposited on silicon substrate were studied by a scanning tunnelling microscopy technique. Measurements completed with spatial resolution up to 1 nm revealed a complex nanoisland structure-rhomboidally ordered near the border of the aluminum-silicon and porous structure in the islands upper parts. Volt-ampere curves demonstrated strong dependency from the film thickness and were interpreted as nanoscale effects. Kelvin probe microscopy was used for simultaneous aluminum-alumina and alumina-air surface scanning.

EEPROM Failure Analysis Methodology : Can Programmed Charges be Measured Directly by Electrical Techniques of Scanning Probe Microscopy (SPM)?

2005 ◽  
Author(s):  
Christophe De Nardi ◽  
Romain Desplats ◽  
Philippe Perdu ◽  
Félix Beaudoin ◽  
Jean Luc Gauffier
Keyword(s):  
Scanning Probe Microscopy ◽  
Floating Gate ◽  
Scanning Probe ◽  
Kelvin Probe ◽  
Oxide Interfaces ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Analysis Methodology ◽  
Electric Force Microscopy

Abstract A method to measure “on site” programmed charges in EEPROM devices is presented. Electrical Scanning Probe Microscopy (SPM) based techniques such as Electric Force Microscopy (EFM) and Scanning Kelvin Probe Microscopy (SKPM) are used to directly probe floating gate potentials. Both preparation and probing methods are discussed. Sample preparation to access floating gate/oxide interfaces at a few nanometers distance without discharging the gate proves to be the key problem, more than the probing technique itself. Applications are demonstrated on 128 kbit EEPROMs from ST Microelectronics and 64 kbit EEPROMs from Atmel.

scholarly journals Atomic Force Microscope Study of Ag-Conduct Polymer Hybrid Films: Evidence for Light-Induced Charge Separation

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1819
Author(s):  
Yinghui Wu ◽  
Dong Wang ◽  
Jinyuan Liu ◽  
Houzhi Cai ◽  
Yueqiang Zhang
Keyword(s):  
Charge Separation ◽  
Electrostatic Force ◽  
High Sensitivity ◽  
Kelvin Probe ◽  
Ag Nps ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Material Systems ◽  
Induced Charge

Scanning Kelvin probe microscopy (SKPM), electrostatic force microscopy (EFM) are used to study the microscopic processes of the photo-induced charge separation at the interface of Ag and conductive polymers, i.e., poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-bʹ]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and poly(3-hexylthiophene-2,5-diyl) (P3HT). They are also widely used in order to directly observe the charge distribution and dynamic changes at the interfaces in nanostructures, owing to their high sensitivity. Using SKPM, it is proved that the charge of the photo-induced polymer PCPDTBT is transferred to Ag nanoparticles (NPs). The surface charge of the Ag-induced NPs is quantified while using EFM, and it is determined that the charge is injected into the polymer P3HT from the Ag NPs. We expect that this technology will provide guidance to facilitate the separation and transfer of the interfacial charges in the composite material systems and it will be applicable to various photovoltaic material systems.

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