Jpn. J. Appl. Phys. 36 (1997) pp. 3318-3323 |Next Article| |Table of Contents|
|Full Text PDF (917K)| |Buy This Article|
Brillouin Scattering from the Soft Optical Phonon in the Orthorhombic Form of a K 3Co 1-xFex(CN) 6 (x≤ 0.03) Crystal
Akira Yoshihara,
Makoto Kurosawa1 and
Yoshiyuki Morioka2
Department of Basic Sciences, Faculty of Science and Engineering, Ishinomaki-Senshu University,
Shinmito, Minamisakai, Ishinomaki 986-80, Japan
1Department of Physics, Faculty of Science, Tohoku University, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-77, Japan
2Department of Chemistry, Faculty of Science, Saitama University, Shimo-okubo, Urawa 388, Japan
(Received October 23, 1996; accepted for publication January 28, 1997)
The soft optical phonon in the two-layer orthorhombic form of a K3Co1-xFex(CN)6 (x≤0.03) single crystal has been reinvestigated using a (3+3)-pass tandem Fabry-Pérot interferometer around the structural phase transition temperature. The soft phonon response can be well described using the phonon-relaxator coupled model. The soft phonon frequency ω∞/2π obeys the |T-T c±|1/2 law except in the vicinity of T c=82.5 ±0.1 K; (ω∞/2π)2=1.20×103(T-82.1) (GHz2) for T>T c and 4.55×103(83.0-T) (GHz2) for T<T c. The soft phonon-relaxator coupling constant increases linearly above the T c as the temperature decreases and the slope becomes steeper below T c. The relaxation time is longer than 40 ps and independent of temperature above T c, but becomes one order of magnitude shorter below T c. The Fe3+ defects seem to be responsible for these unusual temperature dependences.
URL:
http://jjap.jsap.jp/link?JJAP/36/3318/
DOI: 10.1143/JJAP.36.3318
- Y. Morioka and I. Nakagawa: J. Phys. Soc. Jpn. 52 (1983) 23.
- A. Yoshihara, T. Fujimura and Y. Morioka:
J. Phys. Condens. Matter 3 (1991) 5171[IoP STACKS].
- S. M. Lindsay, M. W. Anderson and J. R. Sandercock:
Rev. Sci. Instrum. 52 (1981) 1478[AIP Scitation].
- A. Yoshihara:
Jpn. J. Appl. Phys. 33 (1994) 3100[JSAP].
- R. E. Leese, I. J. Fritz and H. Z. Cummins:
Phys. Rev. B7 (1973) 4165[APS].
- K. B. Lyons and P. A. Fleury:
Phys. Rev. B17 (1978) 2403[APS].
- R. Vacher and L. Boyer:
Phys. Rev. B6 (1972) 639[APS].
- G. Errandonea and J. Sapriel: Solid State Commun. 32 (1979) 391.
- G. Errandonea:
Phys. Rev. B21 (1980) 5221[APS].
- S. M. Shapiro, J. D. Axes, G. Shirane and T. Riste:
Phys. Rev. B6 (1972) 4332[APS].
- Z. Iqbal:
J. Phys. C: Solid State Phys. 10 (1977) 3533[IoP STACKS].
