Control of stoichiometry and morphology in polycrystalline V2O3 thin films using oxygen buffers

Rupp, Jonathan A. J.; Corraze, B.; Besland, Marie-Paule; Cario, Laurent; Tranchant, Julien; Wouters, Dirk J.; Waser, Rainer; Janod, Étienne

doi:10.1007/s10853-020-05028-0

Cited by 4 publications

(5 citation statements)

References 22 publications

(32 reference statements)

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“…27 Besides, a uniform and complete V−Cr substitution in Cr 2 O 3 is possible because V and Cr atoms have very close atomic radius, electronegativity, and valence states. Similarly to published results for powders, 22 (Cr 1−x V x ) 2 O 3 thin films annealed at 800 or 500 °C (either with Cr/Cr 2 O 3 or Fe/ Fe 3 O 4 buffer) led to a substitutional solid solution on the entire range of V/Cr atomic ratio.…”

Section: ■ Results and Discussionsupporting

confidence: 81%

“…It is worth noting that even in an Ar/H 2 gas flow, the residual partial oxygen pressure was in the accurate range (ppO 2 = 10 –21 atm) to oxidize the metallic Cr 1– x V x thin films and obtain the targeted crystallized (Cr 1– x V x ) 2 O 3 phase. As shown in previous works (Rupp et al), thanks to the addition of Cr/Cr 2 O 3 or Fe/Fe 3 O 4 oxygen buffers, the oxygen partial pressure can be accurately controlled down to 10 –37 atm and 10 –23 atm, respectively. Such oxygen pressure range allows obtaining the crystallization of thin films at lower annealing temperature, i.e., 500 °C instead of 800 °C.…”

Section: Resultsmentioning

confidence: 73%

“…The buffers consist of pressed pellets of either 142 mg of Cr/207 mg of Cr 2 O 3 or 73 mg of Fe/100 mg of Fe 3 O 4 . As described by Rupp et al, the use of such buffers guarantees that the annealing atmosphere follows the oxygen partial pressure needed to obtain stoichiometric (Cr 1– x V x ) 2 O 3 thin films when annealing temperature evolves. Besides, annealing at 800 °C in Ar/H 2 (5%) results in an oxygen partial pressure ppO 2 = 10 –21 atm, which ensures an annealing process leading to stoichiometric material …”

Section: Experimental Sectionmentioning

confidence: 99%

“…The buffers consist of pressed pellets of either 142 mg of Cr/207 mg of Cr 2 O 3 or 73 mg of Fe/100 mg of Fe 3 O 4 . As described by Rupp et al, 22 the use of such buffers guarantees that the annealing atmosphere follows the oxygen partial pressure needed to obtain stoichiometric (Cr The chemical compositions and the V/Cr atomic ratios of (Cr 1−x V x ) 2 O 3 single crystals, polycrystalline powders, and thin films were determined by energy-dispersive spectrometry (EDS). A JEOL JSM 5800LV SEM equipped with an energy-dispersive spectrometer SDD SAMx set at 10 kV was used to characterize all samples.…”

Section: ■ Introductionmentioning

confidence: 99%

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Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr_1–xV_x)₂O₃

Rodriguez-Fano,

Haydoura,

Tranchant

et al. 2023

ACS Appl. Mater. Interfaces

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Memories based on the insulator-to-metal transition in correlated insulators are promising to overcome the limitations of alternative nonvolatile memory technologies. However, associated performances have been demonstrated so far only on narrow-gap compounds, such as (V0.95Cr0.05)2O3, exhibiting a tight memory window. In the present study, V-substituted Cr2O3 compounds (Cr1–x V x )2O3 have been synthesized and widely investigated in thin films, single crystals, and polycrystalline powders, for the whole range of chemical composition (0 < x < 1). Physicochemical, structural, and optical properties of the annealed magnetron-sputtered thin films are in very good agreement with those of polycrystalline powders. Indeed, all compounds exhibit the same crystalline structure with a cell parameter evolution consistent with a solid solution over the whole range of x values, as demonstrated by X-ray diffraction and Raman scattering. Moreover, the optical band gap of V-substituted Cr2O3 compounds decreases from 3 eV for Cr2O3 to 0 eV for V2O3. In the same way, resistivity is decreased by almost 5 orders of magnitude as the V content x is varying from 0 to 1, similarly in thin films and single crystals. Finally, a reversible resistive switching has been observed for thin films of three selected V contents (x = 0.30, 0.70, and 0.95). Resistive switching performed on MIM devices based on a 50 nm thick (Cr0.30V0.70)2O3 thin film shows a high endurance of 1000 resistive switching cycles and a memory window R OFF/R ON higher by 3 orders of magnitude, as compared to (Cr0.05V0.95)2O3. This comprehensive study demonstrates that a large range of memory windows can be reached by tuning the band gap while varying the V content in the (Cr1–x V x )2O3 solid solution. It thus confirms the potential of correlated insulators for memory applications.

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Section: ■ Results and Discussionsupporting

confidence: 81%

Section: Resultsmentioning

confidence: 73%

Section: Experimental Sectionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr_1–xV_x)₂O₃

Rodriguez-Fano,

Haydoura,

Tranchant

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

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“…Both glass populations are poor in FeO while in the Nb‐bearing glasses, the Mn concentration is near chondritic (1.1 × CI) and Cr and Ti concentrations are superchondritic indicating fO 2 below IW but above Cr‐Cr 2 O 3 buffers (Rupp et al., 2020) during the glass formation. Thus, depletion of the glasses by FeO could be explained by its metal state under fO 2 below IW in the glass formation region(s).…”

Section: Discussionmentioning

confidence: 99%

Heterogenity of planetesimal collisional plume probed by glass inclusions in metal globules of Sierra Gorda 013, an unusual CBa‐like chondrite

Lorenz

Ivanova

Zinovieva

et al. 2023

Meteorit & Planetary Scien

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Metal‐rich carbonaceous CB chondrites are generally assumed to be materials accreted from the gas–dust plume formed in catastrophic collisions of planetesimals, at least one of which was differentiated into a metal core and silicate shell. Micron‐sized inclusions of siliceous alkali‐rich glasses associated with sulfides were found in the metal globules of the Sierra Gorda 013 (SG 013), a CBa‐like chondrite. These inclusions are unusual carriers of volatile alkalis which are commonly depleted in CB chondrites. The inclusions are presented by two types: (1) Al‐bearing Nb‐poor glass associated with daubréelite and (2) Nb‐bearing Ca,Al,Mg‐poor glass associated with an unknown Na‐bearing Cr‐sulfide. The glass compositions do not correspond to equilibrium condensation, evaporation, or melting. The Nb‐bearing glass has a superchondritic Nb/Ta ratio (31) most likely indicating the fractionation of Nb and Ta in the high‐temperature gas–dust impact plume due to condensation from vapor or evaporation of precursor Nb‐rich particles. The glasses are interpreted as reaction products between refractory plume condensate particles (or possibly planetary or chondritic solids) with relatively low‐temperature K‐Na‐Si‐rich gas in oxidized conditions, possibly in a common plume vapor reservoir. Compositional differences indicate that the glasses and sulfides originated from several different sources under different fO2, fS2, and T conditions and were likely combined together and transported to the metal globule formation region by material flows in the heterogeneous impact plume. The glass–sulfide particles were enclosed in the globules aggregated from smaller solid or molten metal grains. The metal globules were further melted during transport to the high‐temperature plume region or by plume shockwave heating. Thus, the composition of the glasses, the host metal, and the main mass of SG 013 shows dynamic heterogeneity of physical conditions and impact plume composition after a large‐scale planetesimal collision.

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Bulk‐Like Mott‐Transition in Ultrathin Cr‐Doped V₂O₃ Films and the Influence of its Variability on Scaled Devices

Mohr,

Hennen,

Bedau

et al. 2024

Advanced Physics Research

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The pressure‐driven Mott‐transition in Chromium doped V2O3 films is investigated by direct electrical measurements on polycrystalline films with thicknesses down to 10 nm, and doping concentrations of 2%, 5%, and 15%. A change in resistivity of nearly two orders of magnitude is found for 2% doping. A simulation model based on a scaling law description of the phase transition and percolative behavior in a resistor lattice is developed. This is used to show that despite significant deviations in the film structure from single crystals, the transition behavior is very similar. Finally, the influence of the variability between grains on the characteristics of scaled devices is investigated and found to allow for scaling down to at least 50 nm device width.

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Control of stoichiometry and morphology in polycrystalline V2O3 thin films using oxygen buffers

Cited by 4 publications

References 22 publications

Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr_1–xV_x)₂O₃

Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr_1–xV_x)₂O₃

Heterogenity of planetesimal collisional plume probed by glass inclusions in metal globules of Sierra Gorda 013, an unusual CBa‐like chondrite

Bulk‐Like Mott‐Transition in Ultrathin Cr‐Doped V₂O₃ Films and the Influence of its Variability on Scaled Devices

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Control of stoichiometry and morphology in polycrystalline V2O3 thin films using oxygen buffers

Cited by 4 publications

References 22 publications

Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr1–xVx)2O3

Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr1–xVx)2O3

Heterogenity of planetesimal collisional plume probed by glass inclusions in metal globules of Sierra Gorda 013, an unusual CBa‐like chondrite

Bulk‐Like Mott‐Transition in Ultrathin Cr‐Doped V2O3 Films and the Influence of its Variability on Scaled Devices

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Product

Resources

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Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr_1–xV_x)₂O₃

Enhancing the Resistive Memory Window through Band Gap Tuning in Solid Solution (Cr_1–xV_x)₂O₃

Bulk‐Like Mott‐Transition in Ultrathin Cr‐Doped V₂O₃ Films and the Influence of its Variability on Scaled Devices