3D chemical characterization of frozen hydrated hydrogels using ToF-SIMS with argon cluster sputter depth profiling

Residual melanins have been detected in multimillion-year-old animal body fossils; however, confident identification and characterization of these natural pigments remain challenging due to loss of chemical signatures during diagenesis. Here, we simulate this post-burial process through artificial maturation experiments using three synthetic and one natural eumelanin exposed to mild (100 °C/100 bar) and harsh (250 °C/200 bar) environmental conditions, followed by chemical analysis employing alkaline hydrogen peroxide oxidation (AHPO) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results show that AHPO is sensitive to changes in the melanin molecular structure already during mild heat and pressure treatment (resulting, e.g., in increased C-C cross-linking), whereas harsh maturation leads to extensive loss of eumelanin-specific chemical markers. In contrast, negative-ion ToF-SIMS spectra are considerably less affected by mild maturation conditions, and eumelanin-specific features remain even after harsh treatment. Detailed analysis of ToF-SIMS spectra acquired prior to experimental treatment revealed significant differences between the investigated eumelanins. However, systematic spectral changes upon maturation reduced these dissimilarities, indicating that intense heat and pressure treatment leads to the formation of a common, partially degraded, eumelanin molecular structure. Our findings elucidate the complementary nature of AHPO and ToF-SIMS during chemical characterization of eumelanin traces in fossilized organismal remains.

Download Full-text

3D Chemical Characterization of Micron-Sized Coal Fly Ash Particles

MRS Proceedings ◽

10.1557/proc-65-137 ◽

1985 ◽

Vol 65 ◽

Author(s):

Richard W. Linton ◽

Scott R. Bryan ◽

X. B. Cox ◽

Dieter P. Griffis

Keyword(s):

Trace Elements ◽

Fly Ash ◽

Secondary Ion Mass Spectrometry ◽

Coal Fly Ash ◽

Three Dimensional ◽

Depth Profiling ◽

Chemical Characterization ◽

Detection Sensitivity ◽

3D Analysis

The surface layers on coal fly ash particles are of special environmental interest in that concentration enrichments of trace elements may occur [1], thereby enhancing the potential bioavailability of toxic species. Little research, however, has been devoted to the analytical characterization of intraparticle and interparticle distributions of trace elements. The high detection sensitivity, spatial resolution, and depth profiling capabilities of secondary ion mass spectrometry (SIMS), coupled to digital image acquisition and processing [2], permit three-dimensional (3D) compositional maps for collections of individual micron-sized particles. The 3D analysis of trace element distributions in coal fly ash particles is the subject of this SIMS investigation

Download Full-text

Physico-chemical Characterization of Thin Oxide Films: Difficulties and Solutions

MRS Proceedings ◽

10.1557/proc-1073-h05-01 ◽

2008 ◽

Vol 1073 ◽

Author(s):

Thierry Conard ◽

Wilfried Vandervorst

Keyword(s):

Substrate Surface ◽

Depth Profiling ◽

Chemical Characterization ◽

Surface Preparation ◽

High Energy ◽

Thin Layers ◽

Back Side ◽

Gate Stack ◽

Metal Gates

ABSTRACTOxides have always been an integral part of semiconductor manufacturing both in front and back-end processing. With the necessary increase in performance, the demand on these oxides has been increasing leading to their (future) replacement by more complex materials, such as high-k's in gate oxide and metal gates. With the increasing material complexity, a thorough characterization of all aspects of these materials is necessary, covering, for instance, surfaces and interfaces, nucleation, growth, atomic structure, …This article focuses on the characterization of front-end oxides and their interfaces. It shows that detailed information can be achieved by sophisticated experimental techniques such as synchrotron radiation, high energy ERD or AtomProbe but that adequate sample preparation and/or analysis by a combination of more routinely available techniques may achieve similar results. This is shown through the study of three different systems/problems in the gate stack analysis. We will first focus on the determination of substrate surface preparation conditions before deposition and their influence on growth mode and the growth characteristics by different growth techniques (ALD, MOCVD, …). Second, we present the possibilities of compositional depth profiling of thin layers both with nuclear techniques and Angle-Resolved XPS. Finally, we will show that using conventional XPS and a combination of front and back-side analysis, the interface between high-k oxide and metal gates can be investigated. More examples of gate stack characterization can be found elsewhere

Download Full-text

Chemical characterization of SiC and Si3N4 precipitates in multicrystalline silicon by NIR microscopy and ToF-SIMS

physica status solidi (c) ◽

10.1002/pssc.201000346 ◽

2010 ◽

Vol 8 (3) ◽

pp. 796-799 ◽

Cited By ~ 1

Author(s):

Susanne Richter ◽

Kai Kaufmann ◽

Christian Hagendorf

Keyword(s):

Chemical Characterization ◽

Multicrystalline Silicon ◽

Tof Sims

Download Full-text

Chemical characterization of protein based binders in painting samples by means of ToF-SIMS: Tests on ancient and model samples

International Journal of Mass Spectrometry ◽

10.1016/j.ijms.2014.05.001 ◽

2014 ◽

Vol 369 ◽

pp. 9-15 ◽

Cited By ~ 10

Author(s):

A. Atrei ◽

F. Benetti ◽

E. Gliozzo ◽

G. Perra ◽

N. Marchettini

Keyword(s):

Chemical Characterization ◽

Tof Sims

Download Full-text

Surface and chemical characterization of ZnO:Eu3+/Yb3+ spin coated thin films using SEM-CL and TOF-SIMS

Vacuum ◽

10.1016/j.vacuum.2018.09.009 ◽

2018 ◽

Vol 157 ◽

pp. 376-383 ◽

Cited By ~ 5

Author(s):

A. Balakrishna ◽

M.M. Duvenhage ◽

H.C. Swart

Keyword(s):

Thin Films ◽

Chemical Characterization ◽

Tof Sims

Download Full-text

Characterization of size-segregated aerosols using ToF-SIMS imaging and depth profiling

Surface and Interface Analysis ◽

10.1002/sia.5552 ◽

2014 ◽

Vol 46 (7) ◽

pp. 480-488 ◽

Cited By ~ 10

Author(s):

Wenjuan Cheng ◽

Lu-Tao Weng ◽

Yongjie Li ◽

Arthur Lau ◽

Chak Chan ◽

...

Keyword(s):

Depth Profiling ◽

Tof Sims

Download Full-text

Surface Chemical Characterization of Internal Interfaces Generated Within Thin-Film Fe-Ti Hydrides

MRS Proceedings ◽

10.1557/proc-111-369 ◽

1987 ◽

Vol 111 ◽

Author(s):

Jeffrey H. Sanders ◽

Bruce J. Tatarchuk

Keyword(s):

Depth Profiling ◽

Chemical Characterization ◽

Decomposition Process ◽

Surface Chemical ◽

State Information ◽

Size Information ◽

Excellent Candidate ◽

And Migration ◽

Insight Into

AbstractFeTi is considered an excellent candidate for the reversible storage of hydrogen and has been studied extensively in an attempt to understand the bulk activation needed for this material before use. Segregation of TiO2 to the surface has been noted to occur during activation explaining a slight loss of efficiency per hydride cycle, however, characterization by a host of bulk and surface sensitive techniques has not revealed the cause of this decomposition process.10 nm FeTi samples were prepared in a UHV evaporator both with and without palladium coatings. Post treatment characterization was performed with backscatter conversion electron Mossbauer spectroscopy (CEMS), XPS and SIMS. CEMS is a powerful tool for providing stoichiometric, electronic, magnetic, chemical, and particle size information of iron at depths down to 100 nm. XPS and SIMS are useful to gain quantitative and chemical state information from the topmost 2 nm and the topmost monolayer, respectively. Activation treatments consisted of annealing at 573K and 623K followed by reduction at 573K. Results indicate that ppm levels of H2O in H2 are sufficient to decompose the FeTi alloy and produce TiO2 and Fe metal domains at the surface. Also, at 573K in vacuum, a solid-state reaction was found to occur between Fe oxides and FeTi to produce Fe metal and TiO2. The Pd-FeTi interface was probed with CEMS and the results demonstrate hydrogen dissociation and migration in the absence of alloy decomposition. Our approach uses nondestructive-depth profiling of non-Pd coated FeTi samples along with interfacial information from Pd-FeTi specimens to obtain unique insight into the decomposition process.

Download Full-text