Discovery of New Material That Shrinks on Heating -- Twofold shrinkage compared with that of existing materials, compensating for thermal expansion of epoxy resin with addition of small amount of the material- (Press Release)
- Release Date
- 23 Feb, 2015
- BL02B2 (Powder Diffraction)
- BL27SU (Soft X-ray Photochemistry)
Tokyo Institute of Technology
Chuo University
Japan Synchrotron Radiation Research Institute (JASRI)
Kyoto University
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A research group led by Masaki Azuma (professor) of the Materials and Structures Laboratory of Tokyo Institute of Technology discovered a bismuth nickel iron oxide (BiNi1−xFexO3), which has a negative thermal expansion (NTE)*1 that is twofold or more of existing materials at room temperature, in cooperation with researchers from Chuo University, Japan Synchrotron Radiation Research Institute (JASRI), and Kyoto University. The NTE is attributed to the intermetallic charge transfer between Bi and Ni based on the synchrotron X-ray diffraction and absorption spectroscopy studies conducted at BL02B2 and BL27SU of SPring-8. The temperature range of NTE can be controlled by changing the amount of Fe substitution for Ni. Furthermore, the large temperature hysteresis*2, which has been a problem of existing materials, Bi1-xLaxNiO3, can be suppressed. NTE materials are utilized to fabricate zero-thermal-expansion materials*3, in which the thermal expansion of the structural material is compensated, used for systems requiring precise positioning, such as optical communication and semiconductor equipment. The research group confirmed that the addition of a small amount of BiNi1−xFexO3 to epoxy resin results in zero thermal expansion of the composite material. The research group consisted of Koichiro Nabetani, Yuya Muramatsu, Kiho Nakano (all graduate students), Hajime Hojo (assistant professor), and Masaki Azuma (professor) of the Tokyo Institute of Technology; Kengo Oka (assistant professor) of Chuo University; Masaichiro Mizumaki (associate senior scientist) and Yuji Higo (research scientist) of JASRI; Akane Agui (principal researcher) of Japan Atomic Energy Agency; and Naoaki Hayashi (research scientist) and Mikio Takano (professor emeritus, currently, head of Solid State Chemistry Group, Research Institute for Production Development) of Kyoto University. The achievements of this study were published online on 12 February 2015 in the American scientific journal Applied Physics Letters. Publication: |
<<Figures>>
and changes in the lengths of epoxy resin, BiNi0.85Fe0.15O3, and 18 vol% BiNi0.85Fe0.15O3/epoxy resin composite samples measured with strain gauges (right)
The large thermal expansion of epoxy resin is suppressed by the addition of BiNi0.85Fe0.15O3, realizing zero thermal expansion in the temperature range of 300–320 K (27–57 °C).
<<Glossary>>
※1 Negative thermal expansion
In general, the volume and length of materials increase with increasing temperature. Some materials, in contrast, reversibly shrink with increasing temperature. This phenomenon is called negative thermal expansion and is essential for the development of zero-thermal-expansion materials.
※2 Temperature hysteresis
Temperature hysteresis refers to the difference in the length of a material between increasing and decreasing temperature.
※3 Zero-thermal-expansion materials
Materials that do not shrink or expand with changing temperature. Zero-thermal-expansion materials are essential for the precise positioning required for nanotechnology and are realized by combining materials with positive and negative thermal expansion coefficients.
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