scholarly journals Thermal Conductivity of VO2 Nanowires at Metal-Insulator Transition Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2428
Author(s):  
Da Li ◽  
Qilang Wang ◽  
Xiangfan Xu
Keyword(s):  
Thermal Conductivity ◽  
Transition Temperature ◽  
Thermal Conductance ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Size Dependent ◽  
Thermal Bridge ◽  
Heat Carriers ◽  
Conductivity Jump

Vanadium dioxide (VO2) nanowires endowed with a dramatic metal−insulator transition have attracted enormous attention. Here, the thermal conductance of VO2 nanowires with different sizes, measured using the thermal bridge method, is reported. A size-dependent thermal conductivity was observed where the thicker nanowire showed a higher thermal conductivity. Meanwhile, the thermal conductivity jump at metal−insulator transition temperature was measured to be much higher in the thicker samples. The dominant heat carriers were phonons both at the metallic and the insulating regimes in the measured samples, which may result from the coexistence of metal and insulator phases at high temperature. Our results provide a window into exploring the mechanism of the metal−insulator transition of VO2 nanowires.

Size and crystallinity control of dispersed VO2 particles for modulation of metal–insulator transition temperature and hysteresis

CrystEngComm ◽  
2019 ◽  
Vol 21 (38) ◽  
pp. 5749-5756 ◽  
Author(s):  
Wen Zeng ◽  
Haojie Lai ◽  
Tianyin Chen ◽  
Yueheng Lu ◽  
Zhihong Liang ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Solid State ◽  
Synergistic Effect ◽  
Growth Mechanism ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Size Dependent

Growth mechanism of VO2 particles with size dependent crystallinity: a solid-state dewetting and pyrolysis synergistic effect. Crystallinity, strain and defects optimize and modulate the MIT behavior of VO2 particles.

scholarly journals Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1MnO3 and La0.8Y0.1Pb0.1MnO3 Ceramics

2019 ◽  
pp. 33-44 ◽  
Keyword(s):  
Transition Temperature ◽  
Frequency Dispersion ◽  
Insulator Transition ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Solid State Route ◽  
Distorted Structure ◽  
Lower Temperature

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.

Orbital change manipulation metal–insulator transition temperature in W-doped VO2

2015 ◽  
Vol 17 (17) ◽  
pp. 11638-11646 ◽  
Author(s):  
Xinfeng He ◽  
Yijie Zeng ◽  
Xiaofeng Xu ◽  
Congcong Gu ◽  
Fei Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
Infrared Spectroscopy ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
First Principles ◽  
Insulator Transition ◽  
First Principles Calculations ◽  
Orbital Structure ◽  
Metal Insulator Transition ◽  
Metal Insulator

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.

Electroresistance Effect due to Mo Substitution at Mn-Site in Monovalent Doped La0.85Ag0.15Mn1-xMoxO3 (x = 0.00 and 0.05) Manganites

2021 ◽  
Vol 317 ◽  
pp. 17-21
Author(s):  
Muhammad Syazwan Mohd Sabri ◽  
Nur Ain Athirah Che Apandi ◽  
Norazila Ibrahim
Keyword(s):  
Transition Temperature ◽  
Low Temperature ◽  
Temperature Region ◽  
Potential Application ◽  
Insulator Transition ◽  
Applied Current ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Magnetic Inhomogeneity ◽  
Spintronic Devices

The electroresistance, ER effect of La0.85Ag0.15Mn1-xMoxO3 (x = 0.00 and 0.05) samples prepared using solid method are investigated. The increased of applied current from 5 mA to 10 mA does not change the metal-insulator transition temperature, TMI for both samples however decreased the resistivity in the temperature region of 50 K – 300 K. Both samples exhibit large ER effect at low temperature region. At TMI, the ER value is 75.5% (x =0) and decrease to 34.15% (x = 0.05). However, at 300 K, the value of ER increases to 57 % for Mo substituted sample, and the value decreases to 6.4% for the x =0 sample. The enhanced ER effect at 300 K may be due to the growth of conductive filaments under increased applied current. The increase of applied current may perturb the arrangement of magnetic inhomogeneity induced by Mo substitution, result in reduction of resistivity and lead to the observation of ER effect. These findings suggest potential application of La0.85Ag0.15Mn1-xMoxO3 (x = 0.05) in spintronic devices.

Influence of Fe3O4 on metal–insulator transition temperature of La0.7Ca0.3MnO3 thin films

2019 ◽  
Vol 55 (1) ◽  
pp. 99-106
Author(s):  
Xiaofen Guan ◽  
Rongrong Ma ◽  
Guowei Zhou ◽  
Zhiyong Quan ◽  
G. A. Gehring ◽  
...  
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator

The influence of precursors and additives on the hydrothermal synthesis of VO2: A route for tuning the metal–insulator transition temperature

2020 ◽  
Vol 46 (15) ◽  
pp. 23560-23566
Author(s):  
Angélica Marcílio de Souza ◽  
Rodrigo Cercena ◽  
Rodrigo da Costa Duarte ◽  
Sabrina Arcaro ◽  
Alexandre Gonçalves Dal Bó
Keyword(s):  
Transition Temperature ◽  
Hydrothermal Synthesis ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator

Enhancement of thermal conductivity across the metal-insulator transition in vanadium dioxide

2018 ◽  
Vol 113 (6) ◽  
pp. 061902 ◽  
Author(s):  
Lu Chen ◽  
Ziji Xiang ◽  
Colin Tinsman ◽  
Tomoya Asaba ◽  
Qing Huang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Vanadium Dioxide ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator

Magnetic, Electronic - and Magneto - Transport Properties of Nanocrystalline Nd0.6Sr0.4MnO3 Manganites

2009 ◽  
Vol 67 ◽  
pp. 131-136 ◽  
Author(s):  
Kundu Sourav ◽  
Kumar Nath Tapan
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Transition Temperature ◽  
Curie Temperature ◽  
Transport Properties ◽  
Significant Variation ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Low Field

We have reported in this paper, the effect of grain size in Nd0.6Sr0.4MnO3 .We have investigated the effect of grain size on metal-insulator transition and Curie temperature. We have also reported here the variation of low field magnetoresistance with temperature and grain size. We have observed that the Curie temperature increases monotonically with particle size. The metal insulator transition temperature initially increases with particle size and then gets fixed to a certain value. In these Nd0.6Sr0.4MnO3 nanometric systems, any significant variation of magnetoresistance with particle size is not observed.

TRANSPORT PROPERTIES OF Ag-DOPED La0.7Ca0.3MnO3 THIN FILMS ON SILICON SUBSTRATE

2010 ◽  
Vol 24 (27) ◽  
pp. 5451-5456 ◽  
Author(s):  
H. C. JIANG ◽  
W. L. ZHANG ◽  
X. F. CAO ◽  
W. X. ZHANG ◽  
B. PENG
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Transport Properties ◽  
Silicon Substrate ◽  
Annealing Temperature ◽  
Rf Magnetron Sputtering ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Higher Temperature

Ag -doped La 0.7 Ca 0.3 MnO 3 (LCMO) films were prepared on silicon substrate by RF magnetron sputtering. The dependences of transport properties on annealing temperature were explored. It is shown that the resistivity of the samples decreases and the metal–insulator transition temperature shifts to higher temperature with the increase in annealing temperature. Two metal–insulator transition temperatures are presented in the R – T plots of Ag -doped LCMO films, which can be explained by the Ag 1+ substitution of La 3+ to form La 1-x Ag x MnO 3 compound. Compared with LCMO thin films, Ag -doping can observably improve the TM-I and decrease the resistivity of the samples.

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