Theory of morphotropic transformations in vanadium oxides

Katzke, Hannelore; Tolédano, Pierre; Depmeier, Wulf

doi:10.1103/physrevb.68.024109

Cited by 106 publications

(80 citation statements)

References 29 publications

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“…The metal-insulator transitions in the various vanadium oxides V x O y have attracted unimpaired attention since decades for fundamental reasons as well as for possible applications [1][2][3][4]. Among them vanadium dioxide VO 2 is of particular importance because the phase transition slightly above room temperature (T MIT ≈ 340 K) can be easily accessed and -besides single crystalshigh-quality thin films are available.…”

Section: Introductionmentioning

confidence: 99%

Optical properties of VO2 films at the phase transition: Influence of substrate and electronic correlations

Peterseim

Dressel

Dietrich

et al. 2016

Journal of Applied Physics

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Thin films of VO2 on different substrates, Al2O3 and SiO2/Si, have been prepared and characterized from room temperature up to 360 K. From the band structure in the rutile metallic phase and in the monoclinic insulating phase the optical properties are calculated and compared with reflection measurements as a function of temperatures. Various interband transitions can be assigned and compared with previous speculations. We extract the parameters of the metallic charge carriers that evolve upon crossing the insulator-to-metal phase transition and find effects by the substrate. The effect of electronic correlations becomes obvious at the phase transition.

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Section: Introductionmentioning

confidence: 99%

Optical properties of VO2 films at the phase transition: Influence of substrate and electronic correlations

Peterseim

Dressel

Dietrich

et al. 2016

Journal of Applied Physics

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show abstract

“…Among those functional complex oxides, vanadium oxides can adopt a wide range of V:O ratios, resulting in different structural motifs with various types of coordination polyhedra. 7 In this class, vanadium dioxide (VO 2 ) exhibits a number of polymorphic forms, such as VO 2 (M1), VO 2 (M2), VO 2 (M3), VO 2 (R), VO 2 (A), VO 2 (B), and VO 2 (C). The two layered polymorphs VO 2 (A) and VO 2 (B) are promising materials for science and technology.…”

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confidence: 99%

Selective growth of single phase VO2(A, B, and M) polymorph thin films

et al. 2015

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We demonstrate the growth of high quality single phase films of VO2(A, B, and M) on SrTiO3 substrate by controlling the vanadium arrival rate (laser frequency) and oxidation of the V atoms. A phase diagram has been developed (oxygen pressure versus laser frequency) for various phases of VO2 and their electronic properties are investigated. VO2(A) phase is insulating VO2(B) phase is semi-metallic, and VO2(M) phase exhibits a metal-insulator transition, corroborated by photo-electron spectroscopic studies. The ability to control the growth of various polymorphs opens up the possibility for novel (hetero)structures promising new device functionalities.

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“…First, if vanadium is at +IV, the series becomes increasingly oxygen deficient with x (Cr 1−x V x O 2−0.5x ), whereas Cr 3+ -V 5+ pairs would make the series fully stoichiometric. Oxygen-deficient rutiles form Magnéli phases [51], which are structurally clearly different from the parent rutile phase. Since the Cr 1−x V x O 2 series retains the rutile structure, the samples must be near stoichiometric and therefore contain Cr 3+ -V 5+ pairs.…”

Section: A Experimental Resultsmentioning

confidence: 99%

Competition between ferromagnetism and antiferromagnetism in the rutileCr1−xVxO2system

et al. 2016

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We present a comprehensive computational and experimental examination of the Cr 1−x V x O 2 (0 x 0.5) system. The entire series crystallizes in the rutile structure, but the compounds exhibit significantly different magnetic properties depending on x. Lattice parameter a increases linearly with x, but the c parameter is slightly reduced due to vanadium-vanadium bonding. The V-for-Cr substitution creates Cr 3+ -V 5+ pairs; this leads to competition between ferromagnetic (Cr 4+ -Cr 4+ ) and antiferromagnetic (Cr 3+ -Cr 3+ ) interactions such that the materials change from ferromagnetic to antiferromagnetic with increasing x. Weak ferromagnetic interactions arising from Cr 4+ are observed even in the seemingly antiferromagnetic phases with the exception of x = 0.5, which contains only Cr 3+ . Density functional theory calculations are performed, but they incorrectly predict the x = 0.5 phase to be a half-metal. This is caused by an incorrect prediction of the oxidation states of chromium and vanadium.

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Theory of morphotropic transformations in vanadium oxides

Cited by 106 publications

References 29 publications

Optical properties of VO2 films at the phase transition: Influence of substrate and electronic correlations

Optical properties of VO2 films at the phase transition: Influence of substrate and electronic correlations

Selective growth of single phase VO2(A, B, and M) polymorph thin films

Competition between ferromagnetism and antiferromagnetism in the rutileCr1−xVxO2system

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