Thermochemical properties of MnNb2O6

Mansurova, A. N.; Gulyaeva, R. I.; Chumarev, V. M.; Mar'evich, V. P.

doi:10.1007/s10973-010-0783-z

Cited by 14 publications

(5 citation statements)

References 2 publications

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“…9,10 After that, Arroyoy de Dompablo performed a computational study on the stability and electronic properties of oxygen vacancies in MNb 2 O 6 (M = Mn, Fe, Co, Ni, Cu); he found that the oxygen vacancy formation induces (a) a narrowing of the band gap and (b) an electronic density redistribution leading to the reduction of Nb 5+ to lower oxidation states. 11 Additionally, Mansurova supplemented the absence of the thermodynamic properties of MnNb 2 O 6 , 12 and Husson performed Raman study on MnNb 2 O 6 and a theory calculation about the vibration modes. 13,14 At ambient condition, the columbite MnNb 2 O 6 crystallizes in a derivative of the a-PbO 2 -type, in which the oxygen atoms assume a distorted HCP configuration and the cations occupy one-half of the available octahedral interstices.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, the electrical properties of columbite MnNb 2 O 6 have been explored experimentally with the aim of inducing mixed ionic-electronic conductivity. , After that, Arroyoy de Dompablo performed a computational study on the stability and electronic properties of oxygen vacancies in MNb 2 O 6 (M = Mn, Fe, Co, Ni, Cu); he found that the oxygen vacancy formation induces (a) a narrowing of the band gap and (b) an electronic density redistribution leading to the reduction of Nb 5+ to lower oxidation states . Additionally, Mansurova supplemented the absence of the thermodynamic properties of MnNb 2 O 6 , and Husson performed Raman study on MnNb 2 O 6 and a theory calculation about the vibration modes. , …”

Section: Introductionmentioning

confidence: 99%

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Structural Transition of MnNb₂O₆ under Quasi-Hydrostatic Pressure

Huang

Zhou

et al. 2014

J. Phys. Chem. C

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High-pressure Raman scattering and X-ray diffraction studies on manganese niobate (MnNb 2 O 6 ) have been carried out in a diamond anvil cell at room temperature up to 41 GPa. A pressure-induced phase transition was observed at 12 GPa accompanied by the softening of two internal vibration modes ν 10 (B 2g ) and ν 8 (A g ). Disappearing of most Raman vibration peaks under high pressure reveals that the NbO 6 octahedra distort heavily through the transition; this is evidenced by the Xray diffraction results, but the octahedral units still exist, as the internal Nb−O strengthening vibration is observable even at the highest pressure in this study. The equation of state for MnNb 2 O 6 in low pressure phase I was obtained with third-order Birch−Murnaghan method, yielding a zero-pressure bulk modulus B 0 and its pressure derivative B 0 ′ of 154.4 ± 3.5 GPa and 4.1, respectively. The volume dependencies of the optical lattice mode frequencies and their respective Gruneisen parameters were extracted; it is suggested that the instability of the columbite orthorhombic structure at high pressure is related to the strong deformation of the NbO 6 octahedra. Decompression measurements suggest that the pressure-induced transformation is partly reversible.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structural Transition of MnNb₂O₆ under Quasi-Hydrostatic Pressure

Huang

Zhou

et al. 2014

J. Phys. Chem. C

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“…16 Recently, Mansurova et al have investigated the thermochemical properties of MnNb 2 O 6 . 17 As we know, these prominent physical and chemical properties should be associated with its crystal structure. It is well-known that columbite can be considered as a superstructure of R-PbO 2 .…”

Section: Introductionmentioning

confidence: 99%

“…Among them, solid state combination has always been the most popular technique for the synthesis of polycrystalline MnNb 2 O 6 powders, using stoichiometric mixtures of Nb 2 O 5 and MnO or MnCO 3 at high temperatures (≥1100 °C). [3][4][5][6][7][12][13][14]16,17 However, multiple heating and regrinding steps are generally essential to overcome the solid state diffusion barrier. Additionally, the products always have irregular morphology and large particle size.…”

Section: Introductionmentioning

confidence: 99%

Preparation and magnetic and microwave absorption properties of MnNb₂O₆ ellipsoid-like hierarchical structures

et al. 2014

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“…However, the powders obtained by solid-phase processes, which need to be run at high temperatures, have a large particle size. Especially on synthesizing MnNb 2 O 6 , it is necessary not only to heat at 1100 • C or over but also to control the atmosphere conditions carefully [18,19] [33,34]. Each of them have some drawbacks, such as the requirement of removing alkali metals (K, Na) from the prepared powder (1), the need for pretreatment (dissolving Nb 2 O 5 in 40% HF solution for 10 h), or complicated processing (2,3).…”

Section: Introductionmentioning

confidence: 99%