In-Situ Oxygen Isotopic Exchange Vibrational Spectroscopy of Rhenium Oxide Surface Structures on Cerium Oxide

2020 ◽  
Vol 124 (13) ◽  
pp. 7174-7181
Author(s):  
Blake MacQueen ◽  
Benjamin Ruiz-Yi ◽  
Michael Royko ◽  
Andreas Heyden ◽  
Yomaira J. Pagan-Torres ◽  
...  
2009 ◽  
Vol 96 (2) ◽  
pp. 345-356 ◽  
Author(s):  
Orsolya Hakkel ◽  
Zoltán Pászti ◽  
Tamás Keszthelyi ◽  
Krisztina Frey ◽  
László Guczi

1998 ◽  
Vol 120 (1) ◽  
pp. 203-204 ◽  
Author(s):  
Ruchama Fraenkel ◽  
Gordon E. Butterworth ◽  
Colin D. Bain

2001 ◽  
Vol 123 (27) ◽  
pp. 6732-6733 ◽  
Author(s):  
Arndt Heerwagen ◽  
Martin Strobel ◽  
Michael Himmelhaus ◽  
Manfred Buck

2021 ◽  
Vol 39 (6) ◽  
pp. 060405
Author(s):  
Udit Kumar ◽  
Corbin Feit ◽  
S. Novia Berriel ◽  
Ayush Arunachalam ◽  
Tamil Selvan Sakthivel ◽  
...  

Author(s):  
Bruce C. Bunker ◽  
William H. Casey

In Chapters 4 and 5, we demonstrated that local structures and charge distributions have an enormous impact on the equilibrium constants, trajectories, and kinetics of reactions involving soluble oxide precursors. In this chapter, we highlight those features that make reactions on extended oxide surfaces either similar to or dramatically different from the reactions documented in hydrolysis diagrams for each metal cation (see Chapter 5). We first describe oxide surface structures and then discuss how these structures impact both acid–base and ligand-exchange phenomena. In addition to dense oxides, we also introduce some of the chemistry associated with layered materials. Lamellar materials are important from both a fundamental and technological perspective, because water and ions can readily penetrate such structures and provide conditions under which almost every oxygen anion is at an oxide–water interface (see Chapter 10 and Chapter 11). This chapter focuses on oxides containing octahedral cations. The distinctive chemistry of oxides based on tetrahedral cations, including the clay minerals and the zeolites, are the focus of Part Five. The structures of bulk oxides were introduced in Chapter 2. However, for many oxides, the surface structures that interact with aqueous solutions are substantially different from structures found in the bulk. Here, we introduce the basic principles of oxide surfaces that make them chemically active. As a starting point, consider ideal oxide surfaces containing +2 octahedral cations. Pristine oxide surfaces can be created by cleaving perfect crystals in an ultrahigh-vacuum environment. The creation of new surfaces requires an expenditure of energy corresponding to the cohesive energy of the solid, which in turn represents the energy required to break every bond along a given fracture plane. For MgO, the Mg−O bond energy is 380 kJ/mole. Each surface created contains 1.4.1019 oxygen atoms/m2, or 2.4.10−5 moles of bonds. Because two surfaces are created in the fracture event, the initial interfacial energy of each resulting MgO surface is (1/2)(380 kJ/mole)/(2.4_10−5 mole/m2 )=4560 mJ/m2.


2001 ◽  
Vol 7 (S2) ◽  
pp. 1236-1237
Author(s):  
Shelley R. Gilliss ◽  
Jeffrey K. Fairer ◽  
N. Ravishankar ◽  
Mark G. Schwabel ◽  
C. Barry Carter

Cerium oxide is widely used for chemomechanical polishing (CMP) of silicate glasses. Uses include finishing of optical elements and planarizing dielectrics in the semiconductor industry. This study is designed to investigate the fundamentals of the cerium oxide/silica CMP process by measuring the interaction force between silicate glasses and cerium oxide. Surface forces involved in the polishing of glass by a cerium oxide abrasive can be studied in a controlled manner by measuring sample-tip interactions between a glass substrate and a cerium oxide tip in an atomic force microscope (AFM). Commercially available AFM tips have been coated with thin, uniform films of cerium oxide. By using a square pyramid tip as a template for the shape of the cerium oxide film, challenges related to irregular or blunt tip shape can be overcome. However, complete characterization of structure, shape and chemical composition is required before useful information can be obtained using the AFM.


2019 ◽  
Vol 55 (4) ◽  
pp. 541-544 ◽  
Author(s):  
Shuji Ye ◽  
Junjun Tan ◽  
Kangzhen Tian ◽  
Chuanzhao Li ◽  
Jiahui Zhang ◽  
...  

Coherent degenerate infrared-infrared-visible sum frequency generation vibrational spectroscopy provides a powerful label-free probe for identifying the vibrational modes that are coupled through the electronic states in situ and in real time.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5554
Author(s):  
Francesca Ravera ◽  
Esen Efeoglu ◽  
Hugh J. Byrne

Stem cell technology has attracted considerable attention over recent decades due to its enormous potential in regenerative medicine and disease therapeutics. Studying the underlying mechanisms of stem cell differentiation and tissue generation is critical, and robust methodologies and different technologies are required. Towards establishing improved understanding and optimised triggering and control of differentiation processes, analytical techniques such as flow cytometry, immunohistochemistry, reverse transcription polymerase chain reaction, RNA in situ hybridisation analysis, and fluorescence-activated cell sorting have contributed much. However, progress in the field remains limited because such techniques provide only limited information, as they are only able to address specific, selected aspects of the process, and/or cannot visualise the process at the subcellular level. Additionally, many current analytical techniques involve the disruption of the investigation process (tissue sectioning, immunostaining) and cannot monitor the cellular differentiation process in situ, in real-time. Vibrational spectroscopy, as a label-free, non-invasive and non-destructive analytical technique, appears to be a promising candidate to potentially overcome many of these limitations as it can provide detailed biochemical fingerprint information for analysis of cells, tissues, and body fluids. The technique has been widely used in disease diagnosis and increasingly in stem cell technology. In this work, the efforts regarding the use of vibrational spectroscopy to identify mechanisms of stem cell differentiation at a single cell and tissue level are summarised. Both infrared absorption and Raman spectroscopic investigations are explored, and the relative merits, and future perspectives of the techniques are discussed.


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