- 著者
- Shunji Sugai Nobuyuki Kaji Akihito Osuka Koshi Takenaka Shigeru Horii Hiroshi Ikuta
- 出版者
- THE PHYSICAL SOCIETY OF JAPAN
- 雑誌
- Journal of the Physical Society of Japan (ISSN:00319015)
- 巻号頁・発行日
- vol.74, no.3, pp.871-874, 2005-03-15 (Released:2007-12-06)
- 参考文献数
- 26
Optical reflection spectroscopy perpendicular to the double-chain of PrBa2Cu4O8 clarified that carriers in the plane transfer to the chain almost completely as temperature decreases from 295 to 150 K. Many anomalies around 150 K can be explained by the transfer of carriers. The temperature and Zn substitution effects suggest that the chains are in the Fermi liquid state when the carrier density is close to 0.5/Cu(1) and in the Tomonaga–Luttinger liquid state when the carrier density is 0.4/Cu(1).
- 著者
- Ryota Kasugai Yoshifumi Kadowaki Yasunori Yokoyama Naoyuki Katayama Yoshihiko Okamoto Koshi Takenaka
- 出版者
- The Japan Institute of Metals and Materials
- 雑誌
- MATERIALS TRANSACTIONS (ISSN:13459678)
- 巻号頁・発行日
- vol.64, no.3, pp.638-642, 2023-03-01 (Released:2023-02-25)
- 参考文献数
- 30
- 被引用文献数
- 5
For Mg-doped Zn2P2O7, this systematic investigation of co-doping onto Zn sites has elucidated specific effects on negative thermal expansion (NTE). The low-cost and low-environmental-impact NTE material Zn2−xMgxP2O7 shows large NTE in a temperature range including room temperature for x = 0.4. Although Mg doping broadens the operating-temperature window, it remains several dozen degrees wide. Moreover, the total volume change related to NTE becomes less than that of the Zn2P2O7 parent material. Findings obtained from this study demonstrate that co-doping of Mg and of another element onto the Zn site is effective for achieving simultaneous expansion of the operating-temperature window and maintenance of the volume change related to NTE. One illustrative case is that Zn1.64Mg0.30Al0.06P2O7 has a large negative coefficient of linear thermal expansion of about −65 ppm/K at temperatures of 300–375 K. In fact, at temperatures high above room temperature, Zn1.64Mg0.30Al0.06P2O7 powder shows better thermal expansion compensation capability than the composition without Al. The Al-doped phosphates are expected to have broad practical application because of their performance, cost, and environmental load characteristics.