Time-resolved light scattering by photoexcited V2O3

MRS Advances ◽  
2017 ◽  
Vol 2 (23) ◽  
pp. 1231-1236 ◽  
Author(s):  
Nardeep Kumar ◽  
Armando Rúa ◽  
Ramón Díaz ◽  
Iván Castillo ◽  
Brian Ayala ◽  
...  

ABSTRACTUsing ultrafast angle-resolved light scattering technique, we were able to trigger photoinduced phase transition processes in V2O3 film grown on a glass substrate. The phase transition is caused by photoacoustic wave in the film and appears as coherent oscillations of scattering signal at various time scales. These processes strongly depend on the size of microstructures constituting the V2O3 film. One of the key findings of our study is the presence of a size dependent phase transition threshold for V2O3 microstructures, where small size structures ($\tilde <$ 0.5μm) have lowest contribution to the phase transition. The presence of this threshold can be well described by considering uneven internal strain in the films which is one of the key parameters controlling phase transition dynamics in various vanadium oxides.

1983 ◽  
Vol 81 (2) ◽  
pp. 213-220 ◽  
Author(s):  
H J Mlekoday ◽  
R Moore ◽  
D G Levitt

The osmotic permeability coefficient (Pf) was measured with a stopped-flow light-scattering technique. There is an artifactual light-scattering signal produced by the initial mixing that decays with a half-time of approximately 0.2 s. This seriously interferes with the measurement of the osmotically induced change in cell volume, which has a similar half-time. This "injection artifact" is associated with the biconcave shape of the cells. It is negligible for cells that have been made nearly spherical by swelling them in 160 mosmol. The dependence of this artifact on the cell volume may explain the previously observed dependence of Pf on the cell volume. When cells are made echinocytic (and therefore spherically symmetric), this injection artifact becomes negligible at all cell volumes and Pf can be accurately measured. The Pf of echinocytic cells was nearly constant, varying by less than 10% with the direction of flow and the medium osmolarity (160-360 mosmol). The average value of Pf was 2.0 X 10(-2) cm/s (T = 23 degrees C).


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