Synthesis of the Negative Thermal Expansion Compound ZrW&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;8&lt;/sub&gt; by the Spray Drying Technique

Meyer, Christy De; Driessche, Isabel Van; Hoste, Serge

doi:10.4028/www.scientific.net/kem.206-213.11

Cited by 5 publications

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“…The oxide powders were co-milled dry for 24 h in appropriate molar ratios using an attrition mill filled with zirconia balls and a mass ratio of the powder to the balls of 1 : 1. The mixed powders were pressed into bars of 0.3 g using a uniaxial cold press with a steel mould using a pressure of 7.2 ton cm 22 . The synthesis was performed by a conventional solid state reaction at 1453 K for 12 h in a Pt crucible in air.…”

Section: Methodsmentioning

confidence: 99%

Structure and phase transition of Sn-substituted Zr_(1−x)Sn_xW₂O₈

Meyer¹,

Bourée²,

Evans³

et al. 2004

J. Mater. Chem.

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A conventional solid state reaction between ZrO 2 , SnO 2 and WO 3 was used to prepare the negative thermal expansion material Zr (12x) Sn x W 2 O 8 . The strong negative thermal expansion over a broad temperature range, which is well known for the pure zirconium tungstate compound, is also demonstrated in this substituted material. However, the order-disorder phase transition of the cubic materials was shown to shift towards lower temperatures, dependent on the degree of Sn 41 -substitution, by dilatometry and temperature variable X-ray diffraction. This is attributed to the lower bond strength of the Sn-O bond in comparison to the Zr-O bond. The unit cell parameters of the material are significantly smaller due to the insertion of smaller Sn 41 -cations on the Zr 41 -position in the structure. For one composition (x ~0.3), the structure of Zr (12x) Sn x W 2 O 8 was studied by neutron diffraction at two temperatures, 293 K and 473 K, corresponding to respectively the low temperature a-, and high temperature b-polymorph of Zr (12x) Sn x W 2 O 8 . The refined structures were found to be similar to that of ZrW 2 O 8 at the same temperatures. Variable temperature X-ray diffraction of the same sample was used to establish the phase transition temperature, by refining the fractional occupancy of the possible tungstate orientations with temperature.

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Section: Methodsmentioning

confidence: 99%

Structure and phase transition of Sn-substituted Zr_(1−x)Sn_xW₂O₈

Meyer¹,

Bourée²,

Evans³

et al. 2004

J. Mater. Chem.

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“…Nevertheless, in recent years several materials with negative thermal expansion (NTE) have been discovered. Cubic zirconium tungstate [1], ZrW 2 O 8 synthesized by various methods [2][3][4][5][6], is the best known NTE material. It exhibits the unusual negative thermal expansion over a wide range of temperature, from 0.3 K to 1050 K, but it is only stable between 1323 K and 1530 K. When heated to 1050 K in air it decomposes into ZrO 2 and WO 3 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of ZrO2/ZrW2O8 composites with low thermal expansion

Yang

Cheng

Yan

et al. 2007

Composites Science and Technology

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“…An aqueous precursor solution was prepared starting from ammonium metatungstate, (NH 4 ) 6 H 2 W 12 O 40 ·nH 2 O (Aldrich), zirconium oxychloride, ZrOCl 2 ·nH 2 O (Aldrich) and citric acid, as a complexing agent to prevent hydrolysis and precipitation of the salts. 9 The 100 ml 0.042 M W-salt solution was slowly added to 100 ml of a solution containing 0.25 M Zr-solution and 0.25 M citric acid. NH 3 was used to raise the pH of the Zr-solution from 0.3 to 6.…”

Section: Synthesis Of the Compositesmentioning

confidence: 99%

“…Furthermore, the synthesis of the composites will be discussed, including an optimized preparation of ZrW 2 O 8 based on our earlier published spray drying technique. 9 …”

Section: Introductionmentioning

confidence: 99%

Synthesis and thermal expansion of ZrO2/ZrW2O8 composites

Lommens

Meyer

Bruneel

et al. 2005

Journal of the European Ceramic Society

104

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In this work, a ceramic composite of ZrW 2 O 8 and ZrO 2 was synthesized, in order to investigate the possibility of compensating the positive thermal expansion of ZrO 2 with the negative thermal expansion (NTE) compound ZrW 2 O 8 , tailoring the thermal expansion of these composites. The NTE material was mixed with varying amounts of ZrO 2 . The thermal expansion coefficients of this series of composites decrease with increasing amounts of ZrW 2 O 8 . Nevertheless, a negative deviation from the values expected by the rule of mixtures was found to be most pronounced in the middle of the compositional region.

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Synthesis of the Negative Thermal Expansion Compound ZrW<sub>2</sub>O<sub>8</sub> by the Spray Drying Technique

Cited by 5 publications

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Structure and phase transition of Sn-substituted Zr_(1−x)Sn_xW₂O₈

Structure and phase transition of Sn-substituted Zr_(1−x)Sn_xW₂O₈

Synthesis of ZrO2/ZrW2O8 composites with low thermal expansion

Synthesis and thermal expansion of ZrO2/ZrW2O8 composites

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Synthesis of the Negative Thermal Expansion Compound ZrW<sub>2</sub>O<sub>8</sub> by the Spray Drying Technique

Cited by 5 publications

References 0 publications

Structure and phase transition of Sn-substituted Zr(1−x)SnxW2O8

Structure and phase transition of Sn-substituted Zr(1−x)SnxW2O8

Synthesis of ZrO2/ZrW2O8 composites with low thermal expansion

Synthesis and thermal expansion of ZrO2/ZrW2O8 composites

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Product

Resources

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Structure and phase transition of Sn-substituted Zr_(1−x)Sn_xW₂O₈

Structure and phase transition of Sn-substituted Zr_(1−x)Sn_xW₂O₈