High-resolution Kelvin probe microscopy in corrosion science: Scanning Kelvin probe force microscopy (SKPFM) versus classical scanning Kelvin probe (SKP)

2007 ◽  
Vol 53 (2) ◽  
pp. 290-299 ◽  
Author(s):  
Michael Rohwerder ◽  
Florin Turcu
Keyword(s):  
High Resolution ◽  
Kelvin Probe Force Microscopy ◽  
Kelvin Probe ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Scanning Kelvin Probe ◽  
Corrosion Science

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.

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.

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