Phase analysis studies in the copper-niobium-oxygen system

Wahlström, Ebba; Marinder, Bengt‐Olov

doi:10.1016/0020-1650(77)80120-7

Cited by 45 publications

(11 citation statements)

References 6 publications

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“…CuNb 2 O 6 also has two polymorphs, the orthorhombic columbite form, normally present as a single phase above 900°C, and a monoclinic form present between 700° and 900°C 16 . Between these temperatures the two forms can co‐exist, although annealing at 800°–900°C can complete conversion into the columbite CuNb 2 O 6 17 .…”

Section: Resultsmentioning

confidence: 99%

Characterization and Microwave Dielectric Properties of M²⁺Nb₂O₆ Ceramics

Pullar

Breeze

Alford

2005

Journal of the American Ceramic Society

162

130

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This paper details the investigation of the quality factor (Q), dielectric permittivity (e r ) and temperature coefficient of resonant frequency (s f ) of the TE 01d mode of the columbite binary niobate ceramics, with the formula MNb 2 O 6 where M 5 21 cation, in relation to their degree of sintering, microstructure and phase composition. The ceramics were made from a mixed oxide preparative route and fired over a range of temperatures from 8001 to 14001C, and most formed the columbite structure. A comprehensive study was made of the niobates containing the transition metal cations M 5 Mn 21 , Co 21 , Ni 21 , Cu 21 , and Zn 21 , and the group II metal cations M 5 Mg 21 , Ca 21 , Sr 21 , and Ba 21 . All columbite niobates were found to have e r between 17 and 22 and negative s f values between -45 and -76 ppm/1C, and ZnNb 2 O 6 , MgNb 2 O 6 , CaNb 2 O 6 , and CoNb 2 O 6 had high Qf values of 84 500, 79 600, 49 600, and 41 700 GHz, respectively. The Qf of MgNb 2 O 6 was found to rise to over 95 000 GHz when heated at 13001C for 50 h. J ournal

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Section: Resultsmentioning

confidence: 99%

Characterization and Microwave Dielectric Properties of M²⁺Nb₂O₆ Ceramics

Pullar

Breeze

Alford

2005

Journal of the American Ceramic Society

162

130

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“…-CuNb O shows a 1D short-range AFM ordering with ¹ + "20 K(8) and a 3D AFM ordering at ¹ , "7.5 K (9). In contrast, -CuNb O is a spin gap system and its magnetic susceptibility, though analyzed earlier by an isolated spin dimer model (5), is better To whom correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

Examination of the Anisotropic Spin Exchange Interactions of CuM2O6 (M=Sb, V, Nb) by Spin Dimer Analysis

Koo

Whangbo

2001

Journal of Solid State Chemistry

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“…CuNb 2 O 6 has two polymorphs, the black orthorhombic columbite form, normally forming above 900°C, and a yellowish‐green monoclinic form present between 700° and 900°C 18 . Between these temperatures the two forms can coexist, although annealing at 800°–900°C can complete conversion into the orthorhombic CuNb 2 O 6 19 .…”

Section: Introductionmentioning

confidence: 99%

The Synthesis, Properties, and Applications of Columbite Niobates (M²⁺Nb₂O₆): A Critical Review

Pullar

2009

Journal of the American Ceramic Society

148

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A series of ANb 2 O 6 (A=Ca, Mg, Cu, Ni) columbites and 50% Ni doped with CaNb 2 O 6 ,MgNb 2 O 6 and CuNb 2 O 6 has been prepared using sol-gel technique. The samples were sintered at 9000C for 6 hours. Structural characterization of the prepared samples has been done using X-ray diffraction (XRD) method. To study their applicability in low temperature cofired ceramic (LTCC) technology, dielectric and thermal properties have been characterized. Microwave dielectric properties like dielectric constant and Qf values over Ku-band for all the compositions have been measured. Dielectric constant was found to fall between 4.8 to 10. Thermal properties like thermal conductivity and thermal coefficient of expansion (TCE) were measured over a temperature range from room temperature to 900 0C. Thermal conductivity was found to be of the order of 1-2 W/m 0K while TCE was of the order of 5-10 x 10-6/0C. TCE of some of the compositions have shown negative value at 900 0C.

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Phase analysis studies in the copper-niobium-oxygen system

Cited by 45 publications

References 6 publications

Characterization and Microwave Dielectric Properties of M²⁺Nb₂O₆ Ceramics

Characterization and Microwave Dielectric Properties of M²⁺Nb₂O₆ Ceramics

Examination of the Anisotropic Spin Exchange Interactions of CuM2O6 (M=Sb, V, Nb) by Spin Dimer Analysis

The Synthesis, Properties, and Applications of Columbite Niobates (M²⁺Nb₂O₆): A Critical Review

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Phase analysis studies in the copper-niobium-oxygen system

Cited by 45 publications

References 6 publications

Characterization and Microwave Dielectric Properties of M2+Nb2O6 Ceramics

Characterization and Microwave Dielectric Properties of M2+Nb2O6 Ceramics

Examination of the Anisotropic Spin Exchange Interactions of CuM2O6 (M=Sb, V, Nb) by Spin Dimer Analysis

The Synthesis, Properties, and Applications of Columbite Niobates (M2+Nb2O6): A Critical Review

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Characterization and Microwave Dielectric Properties of M²⁺Nb₂O₆ Ceramics

Characterization and Microwave Dielectric Properties of M²⁺Nb₂O₆ Ceramics

The Synthesis, Properties, and Applications of Columbite Niobates (M²⁺Nb₂O₆): A Critical Review