scholarly journals The potential of chemical bonding to design crystallization and vitrification kinetics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christoph Persch ◽  
Maximilian J. Müller ◽  
Aakash Yadav ◽  
Julian Pries ◽  
Natalie Honné ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Predictive Power ◽  
Phase Change Materials ◽  
Glassy Phase ◽  
Covalent Bonding ◽  
Probe Laser ◽  
Pump Probe ◽  
Crystallization Speed ◽  
Real World Applications ◽  
And Calorimetry

AbstractControlling a state of material between its crystalline and glassy phase has fostered many real-world applications. Nevertheless, design rules for crystallization and vitrification kinetics still lack predictive power. Here, we identify stoichiometry trends for these processes in phase change materials, i.e. along the GeTe-GeSe, GeTe-SnTe, and GeTe-Sb2Te3 pseudo-binary lines employing a pump-probe laser setup and calorimetry. We discover a clear stoichiometry dependence of crystallization speed along a line connecting regions characterized by two fundamental bonding types, metallic and covalent bonding. Increasing covalency slows down crystallization by six orders of magnitude and promotes vitrification. The stoichiometry dependence is correlated with material properties, such as the optical properties of the crystalline phase and a bond indicator, the number of electrons shared between adjacent atoms. A quantum-chemical map explains these trends and provides a blueprint to design crystallization kinetics.

Pump-Probe Laser Photolytic Fragmentation Fluorescence Spectrometry of Isomeric Alkenes

1994 ◽  
Vol 48 (5) ◽  
pp. 616-619 ◽  
Author(s):  
Bobby J. Stanton ◽  
E. T. Monroe ◽  
E. L. Wehry
Keyword(s):  
Fluorescence Intensity ◽  
Laser Fluence ◽  
Laser Wavelength ◽  
Fluorescence Spectrometry ◽  
Probe Laser ◽  
Intermediate Species ◽  
Pump Probe ◽  
Laser Pump ◽  
Photolysis Laser ◽  
Spectral Patterns

The two-laser “pump-probe” photolytic fragmentation fluorescence spectrometry of three octenes and two nonenes is described. Probe-laser-induced C2 fluorescence (Deslandres-d'Azambuja system, C1II g→ A1II u) is detected. The relative C2 fluorescence intensity and spectral patterns exhibited by each alkene are strongly dependent on the probe-laser wavelength. The dependence of the fragment fluorescence intensity on the probe-laser fluence implies that the “probe” laser induces photofragmentation of intermediate species produced by the “photolysis” laser.

Electron emission from films of Ag and Au nanoparticles excited by a femtosecond pump-probe laser

2008 ◽  
Vol 77 (19) ◽  
Author(s):  
A. Gloskovskii ◽  
D. A. Valdaitsev ◽  
M. Cinchetti ◽  
S. A. Nepijko ◽  
J. Lange ◽  
...  
Keyword(s):  
Electron Emission ◽  
Au Nanoparticles ◽  
Probe Laser ◽  
Pump Probe

scholarly journals Novel Perspective Coatings for the Optoelectronic Elements: Features of the Carbon Nanotubes to Modify the Surface Relief of BaF2 Materials

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 661
Author(s):  
Natalia Kamanina ◽  
Pavel Kuzhakov ◽  
Dmitry Kvashnin
Keyword(s):  
Carbon Nanotubes ◽  
Quantum Chemical ◽  
Surface Relief ◽  
Covalent Bonding ◽  
Laser Deposition ◽  
Vertical Position ◽  
Laser Technique ◽  
Angle Measurements ◽  
Properties Of Materials ◽  
Interface Materials

It is well known that the optimization of the basic properties of materials is related not only to changes of the substance of the material itself, but can also predict the change of their surface. In this regards, the search for, and study of, new nanostructured coatings based on the laser deposition method becomes extremely promising. Here, we used a laser-oriented deposition technique in order to place carbon nanotubes in a vertical position on the BaF2 surface to modify it. Such modification affected the increasing material transparency, connected with a decrease of the reflection via change the Fresnel losses; hydrophobicity and microhardness as well. Characteristics of the obtained material were studied via spectral analysis, AFM-method, wetting-angle measurements, microhardness estimations to support the possible covalent bonding between the carbon atoms and the interface materials atoms. Moreover, the quantum–chemical calculations completely confirmed the experimental results of the changes of electronic properties of BaF2 substrate after deposition of the CNTs. As the results novel optimized structure based on BaF2 is presented to be used in general optoelectronics, cosmos and laser technique as well.

Electrical pump-probe characterization technique for phase change materials

2016 ◽  
Author(s):  
Faruk Dirisaglik ◽  
Gokhan Bakan ◽  
Sadid Muneer ◽  
Nicholas Williams ◽  
Mustafa Akbulut ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Pump Probe ◽  
Characterization Technique

scholarly journals Photodynamics of alternative DNA base isoguanine

2019 ◽  
Vol 21 (25) ◽  
pp. 13474-13485 ◽  
Author(s):  
Gregory Gate ◽  
Rafał Szabla ◽  
Michael R. Haggmark ◽  
Jiří Šponer ◽  
Andrzej L. Sobolewski ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Pump Probe ◽  
Dna Base ◽  
Photochemical Properties

Pump–probe experiments and quantum-chemical simulations of UV-excited isoguanine elucidate its tautomer dependent photochemical properties.

On the Doppler averaging of susceptibility in pump-probe laser spectroscopy

2015 ◽  
Vol 22 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Gyeong-Won Choi ◽  
Heung-Ryoul Noh
Keyword(s):  
Laser Spectroscopy ◽  
Probe Laser ◽  
Pump Probe

scholarly journals Ti:sapphire-based ultrafast pump-probe laser source in the violet and ultraviolet

1994 ◽  
Author(s):  
George Rodriguez ◽  
Jeffrey P. Roberts ◽  
Antoinette J. Taylor
Keyword(s):  
Laser Source ◽  
Probe Laser ◽  
Pump Probe
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