Metal-to-insulator transition and its effective manipulation studied from investigations in V1-Nb O2 bulks

Zhang, Run; Yin, Chongyang; Fu, Qingshan; Li, Canglong; Qian, Guoyu; Chen, Xinghan; Lu, Ching Liang; Yuan, Songliu; Zhao, Xiujian; Tao, Haizheng

doi:10.1016/j.ceramint.2017.11.024

Cited by 12 publications

(7 citation statements)

References 32 publications

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“…Figure b shows an exploration of the variable-range-hopping (VRH) mechanism, − which has been applied to the electronic transport properties of polycrystalline pellets in the Nb x V 1– x O 2 system previously. ,, This model predicts a linear dependence of ln(ρ) against (1/ T ) β , where β is the power-law constant that is usually between 1/4 and 1/2. Direct comparison tends to be ambiguous, so instead, we plot ln( E loc / k B T ) vs ln( T (K)) for the semiconducting region of x = 0.11 and 0.14 in Figure b (top and bottom panels, respectively), where the local activation energy, E loc , is calculated using the relation …”

Section: Resultsmentioning

confidence: 99%

Geometric Frustration Suppresses Long-Range Structural Distortions in Nb_xV_1–xO₂

et al. 2022

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Though NbO2 and VO2 both exhibit similar electrostructural phase transitions, alloying the two completely suppresses ordering of either kind. It is mostly accepted that impurity ions act as electron-localizing defects, which weaken ordering in a percolative manner. This work reports total X-ray scattering measurements across the Nb x V1–x O2 phase diagram that challenge this prevailing notion. The observations are instead more consistent with the geometric frustration of displacement models recently used to explain the suppression of long-range structural order in the V1–x Mo x O2 phase diagram. Two separate short-range ordered phases are observed in the Nb x V1–x O2 phase diagram, one of which has not been observed before. The structure of this new phase was not determined in the present study, and it is provisionally named 2D-u to indicate that the phase is likely two-dimensional and that it is unknown whether it is a new or existing structure. The other phase, stabilized around 10% Nb substitution, is shown to be structurally equivalent to the 2D-M2 phase that appears at or above 19% Mo substitution, except that it coincides with the insulator side of a metal-to-insulator transition (MIT), while the Mo analog does not. This shows that the MIT intrinsic to VO2 can persist into the quasi-two-dimensionally ordered state.

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Section: Resultsmentioning

confidence: 99%

Geometric Frustration Suppresses Long-Range Structural Distortions in Nb_xV_1–xO₂

et al. 2022

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“…The rutile phase of un-doped VO 2 samples have the largest magnetic moment of 0.07 emu/g, while the 4% Zr-doped samples have the lowest magnetic moment of 0.039 emu/g. For VO 2 rutile phase, it is known that V 4+ ions are periodically arranged in straight chains, with every V 4+ ion having a free electron that contributes a magnetic moment of s = 1/2 [34]. The magnetic moment of the rutile phase arises from the presence of free V 4+ ions and the doped Zr 4+ ions contribute approximately zero to the overall magnetic moment.…”

Section: Resultsmentioning

confidence: 99%

Effect of Zr Doping on the Magnetic and Phase Transition Properties of VO2 Powder

Wang

et al. 2019

Nanomaterials

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In this work, V1−xZrxO2 powder (x = 0, 0.01, 0.02, 0.04) was synthesized by two step hydrothermal method. The micro-topography, magnetic and phase transition properties have been investigated using various measurement techniques. All prepared V1−xZrxO2 powder samples exhibit monoclinic structure at room temperature. With the Zr4+ ions doping concentration increased, the shapes of VO2 particles change from spherical to rectangular slice. Besides, the saturation magnetic moment of the samples decrease with the increase of doped Zr4+ ions concentration, while their phase transition temperature increase gradually with Zr ions doping at a rate of around 2 °C/at% on average. We investigated the Zr doping effects on V-V dimers and confirmed the role of V-V dimers in phase transition. We speculate that more V-V dimers form with Zr doping by magnetic measurements, which result in the monoclinic phase of Zr-doped VO2 sample is more stable than rutile phase. Therefore the phase transition temperature is elevated by Zr doping in our experiment. We further consider that the VO2 phase transition should be ascribed to Peierls transition caused by the changing of V-V dimers.

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“…14 Previous studies focused on modulating SMT behaviors and decreasing the T SMT to room temperature. Some key approaches, including precise control of oxygen vacancies, 21,22 strain engineering 7,23 and heterogeneous elemental doping, [24][25][26] have been suggested to adjust the SMT behaviors of VO 2 thin films to better modulate the practical applications. Among these, doping with heterogeneous ions (such as W 6+ , Mo 6+ , and Nb 6+ ) is the most frequently used approach to decrease T SMT .…”

Section: Introductionmentioning

confidence: 99%

“…For example, R. Zhang et al reported that the T SMT of VO 2 thin films doped with 5% Nb atom concentration was reduced to 277 K, while the degree of changes in resistivity decreased from 6000 times to 30 times. 26 Recently, K. Mulchandani et al demonstrated that by controlling the doping concentration of W 6+ , the T SMT of a VO 2 thin film could be reduced to B27 1C at the expense of lowering the resistivity changes to less than 2 decades. 23 Furthermore, since the phase transition occurs across the grain boundary in the films, some studies have shown that shear propagation influences the SMT behavior and T SMT of VO 2 thin films.…”

Section: Introductionmentioning

confidence: 99%

Effect of microplate size on the semiconductor–metal transition in VO₂ thin films

Guo

Tan

et al. 2022

New J. Chem.

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Metal-to-insulator transition and its effective manipulation studied from investigations in V1-Nb O2 bulks

Cited by 12 publications

References 32 publications

Geometric Frustration Suppresses Long-Range Structural Distortions in Nb_xV_1–xO₂

Geometric Frustration Suppresses Long-Range Structural Distortions in Nb_xV_1–xO₂

Effect of Zr Doping on the Magnetic and Phase Transition Properties of VO2 Powder

Effect of microplate size on the semiconductor–metal transition in VO₂ thin films

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Metal-to-insulator transition and its effective manipulation studied from investigations in V1-Nb O2 bulks

Cited by 12 publications

References 32 publications

Geometric Frustration Suppresses Long-Range Structural Distortions in NbxV1–xO2

Geometric Frustration Suppresses Long-Range Structural Distortions in NbxV1–xO2

Effect of Zr Doping on the Magnetic and Phase Transition Properties of VO2 Powder

Effect of microplate size on the semiconductor–metal transition in VO2 thin films

Contact Info

Product

Resources

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Geometric Frustration Suppresses Long-Range Structural Distortions in Nb_xV_1–xO₂

Geometric Frustration Suppresses Long-Range Structural Distortions in Nb_xV_1–xO₂

Effect of microplate size on the semiconductor–metal transition in VO₂ thin films