SAXS on a chip: from dynamics of phase transitions to alignment phenomena at interfaces studied with microfluidic devices

2017 ◽  
Vol 19 (35) ◽  
pp. 23690-23703 ◽  
Author(s):  
Bruno F. B. Silva
Keyword(s):  
Phase Transitions ◽  
Microfluidic Devices ◽  
Dynamics Of Phase Transitions

Microfluidic devices allow actuation on the microscale, while in situ SAXS allows visualization of these effects in relevant systems.

Rheed Studies of a-Axis Oriented DyBa2Cu3O7 Films Grown by All-MBE

1997 ◽  
Vol 502 ◽  
Author(s):  
Ivan Bozovic ◽  
J. N. Eckstein ◽  
Natasha Bozovic ◽  
J. O'Donnell
Keyword(s):  
Phase Transitions ◽  
Secondary Phase ◽  
Atomic Layer ◽  
High Energy ◽  
Layer By Layer ◽  
Growth Modes ◽  
Flow Surface ◽  
Surface Phase Transitions

ABSTRACTReal-time, in-situ surface monitoring by reflection high-energy electron diffraction (RHEED) has been the key enabling component of atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) of complex oxides. RHEED patterns contain information on crystallographic arrangements and long range order on the surface; this can be made quantitative with help of numerical simulations. The dynamics of RHEED patterns and intensities reveal a variety of phenomena such as nucleation and dissolution of secondary-phase precipitates, switching between growth modes (layer-by-layer, step-flow), surface phase transitions (surface reconstruction, roughening, and even phase transitions induced by the electron beam itself), etc. Some of these phenomena are illustrated here, using as a case study our recent growth of atomically smooth a-axis oriented DyBa2Cu3O7 films.

scholarly journals Phase Transitions in a Perovskite Thin Film Studied by Environmental In Situ Heating Nano‐Beam Electron Diffraction (Small Methods 9/2021)

Small Methods ◽  
2021 ◽  
Vol 5 (9) ◽  
pp. 2170042
Author(s):  
Tobias Meyer ◽  
Birte Kressdorf ◽  
Vladimir Roddatis ◽  
Jörg Hoffmann ◽  
Christian Jooss ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transitions ◽  
Electron Diffraction ◽  
Beam Electron ◽  
In Situ Heating

Phase Transitions in Gold Contacts to Gallium Arsenide

1984 ◽  
Vol 37 ◽  
Author(s):  
Edward Beam ◽  
D. D. L. Chung
Keyword(s):  
Gallium Arsenide ◽  
Phase Transitions ◽  
Peritectic Transformation ◽  
Complete Dissolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating And Cooling ◽  
Similar Phase ◽  
Gold Contacts

AbstractX-ray diffraction was used in situ to study the phase transitions which occurred in 1500 Å Au/GaAs(100) upon heating and cooling. The reaction between Au and GaAs took the form Au + Ga → α Au-Ga. Upon heating, α Au-Ga completely dissolved in liquid Au-Ga. Upon subsequent cooling, β Au-Ga (or Au7Ga2) formed. In 1 atm of nitrogen, phase transitions were observed reversibly at 525 ± 25°C (due to the complete dissolution of α Au-Ga upon heating) and 415 ± 5°C (due to the peritectic transformation of β Au-Ga to α Au-Ga and liquid Au-Ga upon heating). In a vacuum of 425 μ (0.031 Kg/2m) similar phase transitions were observed at 425 ± 25°C and 387 ± 13°C, respectively.

Label-free biosensors based on in situ formed and functionalized microwires in microfluidic devices

The Analyst ◽  
2015 ◽  
Vol 140 (23) ◽  
pp. 7896-7901 ◽  
Author(s):  
Yanlong Xing ◽  
Andreas Wyss ◽  
Norbert Esser ◽  
Petra S. Dittrich
Keyword(s):  
Microfluidic Devices ◽  
Microfluidic System ◽  
Label Free ◽  
System P

Label-free biosensors based on in situ formed and functionalized TTF–Au wires were developed using an integrated microfluidic system.

scholarly journals Phase Transitions in Borohydride Perovskites

2014 ◽  
Vol 70 (a1) ◽  
pp. C73-C73
Author(s):  
Pascal Schouwink ◽  
Radovan Cerny
Keyword(s):  
Phase Transitions ◽  
Volume Expansion ◽  
Host Lattice ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
New Class ◽  
Structural Distortions ◽  
Complex Hydrides ◽  
Type Lattice

A series of complex hydrides based on the highly dynamic tetrahydroborate anion BH4-and crystallizing in theABX3type lattice has recently been discovered. They present a rare case of a family of iono-covalent hydrides that has a genuine tunable host lattice, making them an interesting new class of host compounds for not only the design of hydrogen storage materials but also hydride-properties related to heavy metals. Amongst these, preliminary results onREE-based luminescence will be discussed in the neat and doped compounds, the Ln2+excited states surprisingly not being subject to significant quenching by B-H vibrations. Unlike oxide- or halide-perovskites some members of theAB(BH4)3group do not evolve to higher symmetries as a function of temperature. We show by means ofin-situsynchrotron X-ray powder diffraction, vibrational spectroscopy andab initiocalculations in the solid state, that temperature-induced structural distortions in perovskite-typeACa(BH4)3(A= K, Rb, Cs) have their origin in close hydridic di-hydrogen contacts of repulsive nature. Coupling between internal B-H vibrations and phonons results in lattice distortions that are identical in symmetry to well-known instabilities (soft modes) in perovskites, which generally condense to lower temperatures. Anion-substitution BH4-<->X-(X= Halide) calculated on ordered models can relax distortions caused by repulsive effects. High temperature phase-transitions inACa(BH4)3can be of first or second-order, including 2-fold superlattices, simple cubic-cubic transitions accompanied by volume expansion or complex modulated superstructures accompanied by negative volume expansion, as is the case in RbCa(BH4)3. Close di-hydrogen contacts may be suggested as a tool to tailor the crystal symmetry in complex hydride perovskites in the future.

Sign in / Sign up

Export Citation Format

Share Document