Synthesis and characterisation of transition metal substituted barium hollandite ceramics

ABSTRACTA range of transition metal bearing hollandite phases, formulated Ba1.2B1.2Ti6.8O16 (B2+ = Mg, Co, Ni, Zn, Mn) and Ba1.2B2.4Ti5.6O16 (B3+ = Al, Cr, Fe) were prepared using an alkoxide - nitrate route. X-ray powder diffraction demonstrated the synthesis of single phase materials for all compositions except B = Mn. The processing conditions required to produce > 95 % dense ceramics were determined for all compositions, except B = Mg for which the maximum density obtained was > 93 %. Analysis of transition metal K-edge XANES data confirmed the presence of the targeted transition metal oxidation state for all compositions except B = Mn, where the overall oxidation state was found to be Mn3+. The K-edge EXAFS data of Ba1.2B1.2Ti6.8O16 (B = Ni and Co) were successfully analysed using a crystallographic model of the hollandite structure, with six oxygen atoms present in the first co-ordination shell at a distance of ca. 2.02Å. Analysis of Fe K-edge EXAFS data of Ba1.2B2.4Ti5.4O16 revealed a reduced co-ordination shell of five oxygens at ca. 1.99Å.

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Effect of transition metal oxidation state on crystal structure and magnetic ordering in frustrated A BaM 4 O 7 systems (A= Y, Ca; M= Co, Fe): X-ray diffraction, soft X-ray absorption, and magnetization studies

Current Applied Physics ◽

10.1016/j.cap.2017.11.019 ◽

2018 ◽

Vol 18 (2) ◽

pp. 155-162 ◽

Cited By ~ 4

Author(s):

V.R. Galakhov ◽

D.I. Turkin ◽

V.V. Mesilov ◽

S.N. Shamin ◽

G.V. Bazuev ◽

...

Keyword(s):

Crystal Structure ◽

Transition Metal ◽

Oxidation State ◽

Magnetic Ordering ◽

Metal Oxidation ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Absorption

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X-ray absorption to determine the metal oxidation state of transition metal compounds

10.1063/1.4813463 ◽

2013 ◽

Cited By ~ 1

Author(s):

J. Jiménez-Mier ◽

P. Olalde-Velasco ◽

G. Carabalí-Sandoval ◽

G. Herrera-Pérez ◽

E. Chavira ◽

...

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Transition Metal Compounds ◽

Metal Oxidation ◽

Metal Compounds ◽

X Ray ◽

X Ray Absorption

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Characterisation of K-doped Bi4V2O11 by combined XRD and EPMA: A cautionary tale

Powder Diffraction ◽

10.1017/s0885715600009829 ◽

1997 ◽

Vol 12 (4) ◽

pp. 245-247 ◽

Cited By ~ 1

Author(s):

C. K. Lee ◽

A. M. Coats ◽

A. R. West

Keyword(s):

Powder Diffraction ◽

Electron Probe ◽

Solid Electrolytes ◽

Single Phase ◽

Variable Composition ◽

Cautionary Tale ◽

Phase Purity ◽

X Ray ◽

Phase Pure ◽

Doped Materials

A comparison of X-ray powder diffraction and electron probe microanalyses on samples of Na- and K-doped Bi4V2O11 (BIMEVOX) solid electrolytes indicates some of the problems associated with using XRD to assess phase purity, especially in materials of variable composition such as BIMEVOXes. In this study both the Na- and K-doped materials appeared phase pure by XRD. EPMA indicated the Na-doped materials to be single phase with their expected compositions while the K-containing materials were not phase pure with very little K present in the main BIMEVOX phase.

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Synthesis, Structure, and Characterization of La1−xBax (0 ≤ x ≤ 1)

MRS Proceedings ◽

10.1557/proc-271-107 ◽

1992 ◽

Vol 271 ◽

Author(s):

Joseph E. Sunstrom ◽

Susan M. Kauzlarich

Keyword(s):

Magnetic Susceptibility ◽

Powder Diffraction ◽

Single Phase ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Temperature Dependent ◽

X Ray ◽

Early Transition Metal ◽

Arc Melting

ABSTRACTThe compounds La1−xBaxTiO3 (0 ≤ × ≤ 1) have been prepared by arc melting stoichiometric amounts of LaTiO3 and BaTiO3. Single phase samples can be made for the entire stoichiometry range. The polycrystalline samples have been characterized by thermal gravimetric analysis, X-ray powder diffraction, and temperature dependent magnetic susceptibility. This series of compounds has been studied as a possible candidate for an early transition metal superconductor.

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Impact of transition metal oxidation state on the multiferroic properties and magnetoelectric coupling strength of BST ceramics

Journal of Asian Ceramic Societies ◽

10.1080/21870764.2020.1793473 ◽

2020 ◽

Vol 8 (3) ◽

pp. 804-813

Author(s):

Aanchal Chawla ◽

Anupinder Singh ◽

P. D. Babu ◽

Mandeep Singh

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Coupling Strength ◽

Magnetoelectric Coupling ◽

Metal Oxidation ◽

Multiferroic Properties ◽

Bst Ceramics

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Ternary transition metal gallides with TiNiSi, ZrBeSi and MgZn2-type structure

Zeitschrift für Naturforschung B ◽

10.1515/znb-2019-0002 ◽

2019 ◽

Vol 74 (3) ◽

pp. 297-306 ◽

Cited By ~ 1

Author(s):

Lukas Heletta ◽

Theresa Block ◽

Steffen Klenner ◽

Rainer Pöttgen

Keyword(s):

Transition Metal ◽

Powder Diffraction ◽

Metallic Iron ◽

Site Occupancy ◽

Laves Phase ◽

Structural Motif ◽

Equiatomic Composition ◽

Laves Phases ◽

X Ray ◽

Arc Melting

AbstractA series of ternary transition metal gallides around the equiatomic composition have been synthesized from the elements by arc-melting and subsequent annealing. The compounds crystallize with site occupancy variants of the hexagonal Laves phase MgZn2, with the hexagonal ZrBeSi or the orthorhombic TiNiSi type. All samples have been characterized on the basis of their lattice parameters, determined by X-ray powder diffraction (Guinier technique). The structures of NbCr1.58Ga0.42 and NbFe1.51Ga0.49 (MgZn2 type, P63/mmc), NbRhGa (ZrBeSi type, P63/mmc), and ScNiGa, ScPtGa and ScAuGa (TiNiSi type, Pnma) were refined from single crystal X-ray diffractometer data. The ScPtGa and ScAuGa crystals showed trilling formation. Mixed site occupancies were only observed in the Laves phases while all other crystals were well ordered. A striking structural motif of NbRhGa is the formation of niobium chains (264 pm Nb–Nb) along the c axis. Several gallides were magnetically characterized. They are Pauli paramagnets. The two crystallographically independent iron sites in the Laves phase TaFeGa could be distinguished in the 57Fe Mössbauer spectrum. The isomer shifts of 0.06(3) (Fe1) and –0.02(3) (Fe2) mm s−1 indicate metallic iron.

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Transition Metal Pnictide Synthesis: Self Propagating Reactions Involving Sodium Arsenide, Antimonide and Bismuthide

Zeitschrift für Naturforschung B ◽

10.1515/znb-1994-0408 ◽

1994 ◽

Vol 49 (4) ◽

pp. 477-482 ◽

Cited By ~ 12

Author(s):

Andrew L. Hector ◽

Ivan P. Parkin

Keyword(s):

Transition Metal ◽

Powder Diffraction ◽

Metal Halides ◽

X Ray ◽

Ft Ir ◽

Cu And Zn

Initiation of the reaction between Na 3E (E = As, Sb, Bi) and anhydrous metal halides at 25 to 550 °C produces metal arsenides MxAsy (M=Y,La, Ti, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Pt ,Cu and Zn) and antimonides MxSby (M=Ti, V, Nb, Ta, Cr, Fe, Co, Ni, Pt, Cu and Zn) via an exothermic selfpropagating reaction. The metal arsenides were characterized by X-ray powder diffraction, SEM/EDAX , microanalysis and FT-IR.

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Synthesis and Characterization of T12Ba2CaCu2O8 and T12Ba2Ca2Cu3O10

MRS Proceedings ◽

10.1557/proc-169-357 ◽

1989 ◽

Vol 169 ◽

Author(s):

Lauren E. H. McMills ◽

Shu Li ◽

Zhen Zhang ◽

Martha Greenblatt

Keyword(s):

Magnetic Susceptibility ◽

Powder Diffraction ◽

Single Phase ◽

Synthesis And Characterization ◽

Synthetic Method ◽

Superconducting Properties ◽

X Ray ◽

Preparation Conditions ◽

The Relationship

AbstractSingle-phase samples of T12Ba2CaCu2O8 and T12Ba2Ca2Cu3O10 have been prepared using a reliable and simple synthetic method. Samples were characterized by x-ray powder diffraction, magnetic susceptibility and four probe resistivity methods. The TcR=0 values for T12Ba2CaCu2O8 ranged from 100 to 105K, whereas those for T12Ba2Ca2Cu3O10 ranged from 96 to 107K. The relationship between the superconducting properties and the various preparation conditions are discussed.

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