A Study of the Pressure-Induced Phase Transition in Bulk and Nanocrystalline Cadmium Sulfide

1989 ◽  
Vol 164 ◽  
Author(s):  
Xue-Shu Zhao ◽  
John Schroeder ◽  
Peter D. Persans ◽  
Enlian Lu
Keyword(s):  
Phase Transition ◽  
Raman Scattering ◽  
Wurtzite Phase ◽  
First Order ◽  
Pressure Tuning ◽  
First Order Phase Transition ◽  
Resonant Raman ◽  
Resonant Raman Scattering ◽  
First Order Phase ◽  
Colloidal Cds

AbstractWe have used Resonant Raman scattering induced by pressure tuning to study the phase transition and electronic states of bulk and 60±20 Å colloidal microcrystallite CdS. The experimental results show that bulk CdS undergoes a well-defined first order phase transition at 27 kbar and that the intensity of the Raman scattering increases sharply when the level of the intermediate state (bound exciton I2) is close to the photon energy. After the phase transition no Raman scattering and photoluminescence can be observed. However, the phase transition in the colloidal CdS is quite different from the bulk CdS and the complete phase transition occurs above 60 kbar. Both bulk and colloidal CdS reverse to the original wurtzite phase after releasing the pressure.

First order phase transition of Li3ThF7at 281 K: A comparative study between EPR and Raman scattering

2001 ◽  
Vol 155 (1-4) ◽  
pp. 361-366 ◽  
Author(s):  
K. Krambrock ◽  
K. J. Guedes ◽  
M. V. B. Pinheiro ◽  
C. J. Franco ◽  
M. A. S. Oliveira ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Scattering ◽  
Comparative Study ◽  
Order Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase

scholarly journals Gravitational wave signals of dark matter freeze-out

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Danny Marfatia ◽  
Po-Yan Tseng
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Order Phase Transition ◽  
First Order ◽  
Stochastic Background ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
First Order Phase ◽  
Freeze Out

Abstract We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the measured dark matter relic abundance via (1) bubble filtering, and (2) inflation and reheating, and show that gravitational waves from these mechanisms are detectable at future interferometers.

scholarly journals Dark Matter production from relativistic bubble walls

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Aleksandr Azatov ◽  
Miguel Vanvlasselaer ◽  
Wen Yin
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Matter Production ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
Higgs Portal ◽  
First Order Phase ◽  
Gravitational Background

Abstract In this paper we present a novel mechanism for producing the observed Dark Matter (DM) relic abundance during the First Order Phase Transition (FOPT) in the early universe. We show that the bubble expansion with ultra-relativistic velocities can lead to the abundance of DM particles with masses much larger than the scale of the transition. We study this non-thermal production mechanism in the context of a generic phase transition and the electroweak phase transition. The application of the mechanism to the Higgs portal DM as well as the signal in the Stochastic Gravitational Background are discussed.

Discovering a First-Order Phase Transition in the Li–CeO2 System

Nano Letters ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 1282-1288 ◽  
Author(s):  
Kaikai Li ◽  
Xiaoye Zhou ◽  
Anmin Nie ◽  
Sheng Sun ◽  
Yan-Bing He ◽  
...  
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase
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