scholarly journals Modelling the enthalpy change and transition temperature dependence of the metal–insulator transition in pure and doped vanadium dioxide

2020 ◽  
Vol 22 (24) ◽  
pp. 13474-13478
Author(s):  
Haichang Lu ◽  
Stewart Clark ◽  
Yuzheng Guo ◽  
John Robertson

We show that a non-collinear spin density GGA+U functional calculation can describe the enthalpy difference (latent heat) of ΔE0 = −44.2 meV per formula unit, similar to the experimental value, between the paramagnetic rutile and the M1 phases of VO2.

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.


AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035120
Author(s):  
Kazuma Tamura ◽  
Teruo Kanki ◽  
Shun Shirai ◽  
Hidekazu Tanaka ◽  
Yoshio Teki ◽  
...  

The present work studies the microstructural and electrical properties of La0.9Pb0.1MnO3 and La0.8Y0.1Pb0.1MnO3 ceramics synthesized by solid-state route method. Microstructure and elemental analysis of both samples were carried out by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) method, respectively. Phase analysis by X-ray diffraction (XRD) indicated formation of single phase distorted structure. The XRD data were further analyzed by Rietveld refinement technique. Raman analysis reveals that Y atom substitutes La site into the LPMO with shifting of phonon modes. The temperature variation of resistivity of undoped and Y-doped La0.9Pb0.1MnO3 samples have been investigated. The electrical resistivity as a function of temperature showed that all samples undergo an metal-insulator (M-I) transition having a peak at transition temperature TMI. Y-doping increases the resistivity and the metal-insulator transition temperature (TMI) shifts to lower temperature. The temperature-dependent resistivity for temperatures less than metal-insulator transition is explained in terms the quadratic temperature dependence and for T > TMI, thermally activated conduction (TAC) is appropriate. Variation of frequency dispersion in permittivity and loss pattern due to La-site substitution in LPMO was observed in the dielectric response curve.


2001 ◽  
Vol 64 (18) ◽  
Author(s):  
S. Klimm ◽  
M. Herz ◽  
R. Horny ◽  
G. Obermeier ◽  
M. Klemm ◽  
...  

2015 ◽  
Vol 17 (17) ◽  
pp. 11638-11646 ◽  
Author(s):  
Xinfeng He ◽  
Yijie Zeng ◽  
Xiaofeng Xu ◽  
Congcong Gu ◽  
Fei Chen ◽  
...  

Using ultraviolet-infrared spectroscopy and first principles calculations, it is revealed that changes in the orbital structure can regulate the W-doped VO2 phase transition temperature.


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