Analytical techniques for studying and characterizing polymorphs and polymorphic transitions

2020 ◽  
pp. 136-214
Author(s):  
Joel Bernstein
Keyword(s):  
Analytical Techniques ◽  
Scanning Tunneling ◽  
Gravimetric Analysis ◽  
Tunneling Microscopy ◽  
Scanning Calorimetry ◽  
Thermal Methods ◽  
Polymorphic Transitions ◽  
Force Microscopy ◽  
Analytical Tools

Chapter 4 deals with the analytical methods for the characterization of solid forms, including optical and hot stage microscopy, thermal methods (differential scanning calorimetry, thermal gravimetric analysis, etc.), X-ray diffraction methods (powder and single crystal methods), infrared and Raman spectroscopy, solid state nuclear magnetic resonance spectroscopy, electron microscopy, atomic force microscopy, scanning tunneling microscopy, and pycnometry (density measurements). The principles of each of these techniques are outlined, followed by representative examples of their application in the investigation and characterization of polymorphic systems. The integration of a number of analytical tools—“hyphenated techniques”—into a particular instrument is described for a number of cases, followed by a discussion of the experimental approach for determining if two samples comprise polymorphs of the same compound.

Heterogeneous Oxidation and Precipitation of Aqueous Mn(II) at the Goethite Surface: A SPM Study

1998 ◽  
Vol 4 (S2) ◽  
pp. 600-601
Author(s):  
John Rakovan ◽  
F. Hochella Michael
Keyword(s):  
Lateral Force ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Mineral Surfaces ◽  
Tunneling Microscopy ◽  
Heterogeneous Oxidation ◽  
Force Microscopy ◽  
Solution Interface ◽  
Atomic Force

Since its invention inl982 scanning probe microscopy (SPM) has become an important analytical tool in every branch of physical science. The two most widely used types of SPM are atomic force Microscopy (AFM) and scanning tunneling microscopy (STM). Both AFM and STM allow measurement of the microtopography of a surface down to the atomic scale. Many spin-off applications such as lateral force and magnetic force allow measurement of a variety of the physical properties of a surface while imaging its microtopography. SPM can be done in both air and liquid and hence can be used to observe the interactions that take place at a solid-solution interface.SPM has been used in mineralogy and geochemistry since 1989. Here as in other applications the great strength of SPM is in the characterization of the heterogeneous nature of mineral surfaces and the ability to observe many geochemical processes in real time.

Multiparameter Imaging and Understanding the Role of the Tip - Atomic Resolution Images of Rutile TiO2 (110)

2011 ◽  
Vol 1318 ◽  
Author(s):  
S. J. O’Brien ◽  
H. Ozgur Ozer ◽  
G. L. W. Cross ◽  
J. B. Pethica
Keyword(s):  
Barrier Height ◽  
Local Density ◽  
Chemical Species ◽  
Analytical Techniques ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Simultaneous Acquisition ◽  
Stm Images

ABSTRACTA major challenge for scanned probe microscopy is to identify structures and chemical species on a surface, which have not already been inferred from other analytical techniques. Progress is impeded by the fact that in general the structure and composition of the tip atom is not known. To illustrate some of the issues involved, we report simultaneous scanning tunneling microscopy/atomic force microscopy (STM/AFM) of the TiO2 (110) surface. The use of small amplitudes enabled the simultaneous acquisition of force gradient and barrier height images during standard STM imaging. Surprisingly, we find most STM images exhibit a corrugation contrast inverse to that usually reported in the literature. However, regardless of the contrast in STM, force gradient images always showed greater attraction over O rows. Barrier height images also show this consistency, always being greater over O rows. This supports the theoretical model of the electronic structure of the surface, but shows that the tip structure and interaction cannot be ignored in modeling STM images. We conclude that there is a fine balance between topography and local density of states (LDOS) in STM imaging of this surface; which of them dominates the STM image is determined by the tip. Simultaneous multi-parameter imaging is useful in interpreting images reliably, particularly on multi-component surfaces.

Characterization of InP/GaInAs Nanometer Sized Columns Produced by Aerosol Deposition and Plasma Etching

1994 ◽  
Vol 332 ◽  
Author(s):  
I. Maximov ◽  
K. Deppert ◽  
L. Montelius ◽  
L. Samuelson ◽  
S. Gray ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Electron Cyclotron Resonance ◽  
Average Diameter ◽  
Aerosol Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ag Particles

ABSTRACTWe present a technique for the fabrication of InP nano-columns and GaInAs/InP quantum-dots based on the use of sintered aerosol Ag particles as a mask in an electron cyclotron resonance etching process. The sintered particles have much more regular shapes than the unsintered ones used in previous studies and are more resistant to the etching environment, which results in the formation of more regular and reproducible structures. For example, we have been able to produce columns 100 nm in height which have an average diameter of 24 nm and a density of 109 cm−2.We have investigated the shape of the etched columns as a function of the Ag particles’ size, and characterized their electrical and optical properties using a combination of scanning electron microscopy, scanning tunneling microscopy, atomic force microscopy, and photoluminescence.

Local Characterization of Ultrathin ZnO Layers on Ag(111) by Scanning Tunneling Microscopy and Atomic Force Microscopy

2014 ◽  
Vol 118 (47) ◽  
pp. 27428-27435 ◽  
Author(s):  
Akitoshi Shiotari ◽  
Bo Hong Liu ◽  
Simon Jaekel ◽  
Leonhard Grill ◽  
Shamil Shaikhutdinov ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Scanning Tunneling Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Local Characterization
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