Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-09T12:52:42.214Z Has data issue: false hasContentIssue false
  • English
  • Français

Sound Velocity Study of Bechgaard Salts (TMTSF)2PF6 and (TMTSF)2ClO4

Published online by Cambridge University Press:  25 February 2011

X. D. Shi ,
L. Chiang ,
R. Upasani  and
P. M. Chaikin
X. D. Shi
Affiliation:
Dept. of Physics, Univ. of Pennsylvania, Phila., PA 19104 Dept. of Physics, Princeton Univ., Princeton, NJ 08544
L. Chiang
Affiliation:
Exxon Research and Eng. Co., Route 22 East,Annandale, NJ 08801
R. Upasani
Affiliation:
Exxon Research and Eng. Co., Route 22 East,Annandale, NJ 08801
P. M. Chaikin
Affiliation:
Dept. of Physics, Princeton Univ., Princeton, NJ 08544 Exxon Research and Eng. Co., Route 22 East,Annandale, NJ 08801
Get access

Abstract

We have studied the elastic properties of the Bechgaard salts (TMTSF)2PF6 and (TMTSF)2C104 through their Spin Density Wave (SDW) and anion ordering transitions. Using a vibrating reed technique to measure the sound velocity and attenuation, we observed a large softening of sound velocity immediately above the SDW transition temperature, 12K, of (TMTSF)2PF6 followed by a large hardening below the transition. The softening results from a strong dependence of Tc on stress in the most conducting direction, while the hardening results from the loss of screening from the conduction electrons and yields a value for the long wavelength electron-phonon coupling constant. The anion ordering transition at 24K in (TMTSF)2ClO4 is marked by a hardening of the lattice that is considerably larger than expected from the lattice constant changes. Our most interesting finding, however, is the observation of a series of steps in the sound velocity as the Field Induced Spin Density Wave (FISDW) transitions are crossed by increasing the magnetic field at low temperatures. The fact that the sound velocity steps are small at the beginning of the cascade of transitions and increase with field, even as extrapolated to low temperature, is an unexpected result from present theory and may indicate a more direct coupling of the lattice stiffness to the SDW order parameter.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 173: Symposium Q – Advanced Organic Solid State Materials , 1989 , 239
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Jerome, D. and Schultz, H.J., Adv. Phys. 31, 299 (1982)Google Scholar
[2] Heritier, M., Montambaux, G. and Lederer, P., J. Physique Lett. 45 L943 (1984)CrossRefGoogle Scholar
[3] Naughton, N.J., Brooks, J.S., Chiang, L.Y., Chamberlin, R.V., and Chaikin, P.M., Phys. Rev. Lett. 55, 969 (1985)Google Scholar
[4] Pesty, F., Garoche, P. and Bechgaard, K., Phys. Rev. Lett. 55, 2495 (1985)Google Scholar
[5] Naughton, N.J., Chamberlin, R.V., Yan, X., Hsu, S.-Y., Chiang, L.Y. Azbel, M.Ya., and Chaikin, P.M., Phys. Rev. Lett. 61, 621 (1988)Google Scholar
[6] Chaikin, P. M., Tiedje, T. and Bloch, A.N., Solid St. Commun. 41, 739 (1982)CrossRefGoogle Scholar
[7] Bechgaard, K.,Jacobsen, C.S.,Montensen, K.,Pedersen, H.J. and Throup, N., Solid St. Commun. 33, 1119(1980)Google Scholar
[8] Brill, J.W. and Roark, W., Phys. Rev. Lett. 53 846 (1984)Google Scholar
[9] Xiang, X.D. and Brill, J.W., Phys. Rev. Lett. 63, 1853(1989)Google Scholar
[10] Maki, Kazumi and virosztek, Attila, Phys. Rev. B36, 2910 (1987)Google Scholar
[11] Rice, M.J., Low Dimensional Cooperative Phenomena (edited by Keller, H.J.), p.23, Plenum Press, New York (1975)Google Scholar
[12] Testardi, L.R., Phys. Rev. B12, 3849 (1975)Google Scholar
[13] Barmatz, M., Testardi, L.R. and Salvo, F.J.Di, Phys. Rev. B12, 4367 (1975)Google Scholar
[14] Tiedje, T., Haering, R.R. and Hardy, W.N., J. Acoust. Soc. Am. 65(5) 1171(1979)Google Scholar
[15] Pesty, F. and Garoche, P., Low Dimentional Systems and Molecular Devices (Edited By Metzger, R. M. ), NATO-ASI, Plenum PressGoogle Scholar
[16] Gaonach, C., Creuzet, G. and Noguera, C., J. Physique 48, 107(1987)Google Scholar
[17] Nakane, Y. J. Phys. Soc. Jpn. 55, 2235(1986)Google Scholar