scholarly journals Optically Monitored Electric-Field-Induced Phase Transition in Vanadium Dioxide Crystal Film

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 764
Author(s):  
Peng-Fei Wang ◽  
Qianqian Hu ◽  
Tan Zheng ◽  
Yu Liu ◽  
Xiaofeng Xu ◽  
...  

Vanadium dioxide (VO2), due to its electrically induced metal-to-insulator transition with dramatic changes in electrical and optical properties, is considered to be a powerful material for electro-optical devices. However, there are still some controversies about phase transition mechanism under voltage. Here, based on optical characterizations on VO2 crystal nanofilm during the whole process of phase transition, temporal evolution and spatial distribution of changes in electricity, optic and temperature are investigated simultaneously, to explore the mechanism. The variations of Raman spectrum and reflected spectrum, and changes in current and temperature are evidences for occurrence of phase transition, which exhibit different changing behaviors with time and space. These results offer a better understanding of the phase transition mechanism, implying that lattice structure of VO2 changes gradually after applying voltage until the structure is completely converted to metallic structure, which causes a rapid increase in carrier density, resulting in a rapid change in current, reflected spectrum and temperature. Temperature rise before phase transition and applied electric field alone are not enough for triggering metal-insulator transition, but these two factors can act synergistically on structural transformation to induce phase transition.

2018 ◽  
Vol 10 (7) ◽  
pp. 581-605 ◽  
Author(s):  
Zewei Shao ◽  
Xun Cao ◽  
Hongjie Luo ◽  
Ping Jin

2017 ◽  
Vol 29 (39) ◽  
pp. 1702162 ◽  
Author(s):  
Wuhong Xue ◽  
Gang Liu ◽  
Zhicheng Zhong ◽  
Yuehua Dai ◽  
Jie Shang ◽  
...  

Science ◽  
2018 ◽  
Vol 362 (6414) ◽  
pp. 572-576 ◽  
Author(s):  
Simon Wall ◽  
Shan Yang ◽  
Luciana Vidas ◽  
Matthieu Chollet ◽  
James M. Glownia ◽  
...  

Many ultrafast solid phase transitions are treated as chemical reactions that transform the structures between two different unit cells along a reaction coordinate, but this neglects the role of disorder. Although ultrafast diffraction provides insights into atomic dynamics during such transformations, diffraction alone probes an averaged unit cell and is less sensitive to randomness in the transition pathway. Using total scattering of femtosecond x-ray pulses, we show that atomic disordering in photoexcited vanadium dioxide (VO2) is central to the transition mechanism and that, after photoexcitation, the system explores a large volume of phase space on a time scale comparable to that of a single phonon oscillation. These results overturn the current understanding of an archetypal ultrafast phase transition and provide new microscopic insights into rapid evolution toward equilibrium in photoexcited matter.


2002 ◽  
Vol 20 (1) ◽  
pp. 148-150 ◽  
Author(s):  
Xu Shi-Qing ◽  
Ma Hong-Ping ◽  
Dai Shi-Xun ◽  
Jiang Zhong-Hong

2014 ◽  
Vol 16 (19) ◽  
pp. 8783-8786 ◽  
Author(s):  
Qiang Song ◽  
Weitao Gong ◽  
Guiling Ning ◽  
Hassan Mehdi ◽  
Guiqi Zhang ◽  
...  

A synergic effect of sodium on the metal–insulator transition temperature reduction of tungsten-doped vanadium dioxide is noted.


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