Anomalous behavior of the specific heat and upper critical magnetic field in the superconducting single crystal La1.85Sr0.15CuO4
Tóm tắt
The specific heat and resistive upper critical magnetic field of the single crystal La1.85Sr0.15CuO4 are investigated in the temperature range 2–50 K in magnetic fields up to 8 T for two directions of the magnetic field, parallel and normal to the ab crystalline plane. For both orientations a nonlinear (close to square root) magnetic field dependence of the mixed-state specific heat and a positive curvature of the temperature dependence of the upper critical magnetic field are observed. Neither of these anomalies is described by standard theories of superconductivity. Within the framework of the thermodynamic relations it is shown that in a type-II superconductor a relationship exists between the temperature dependence of the critical magnetic field and the field dependence of the specific heat. The anomalies observed in these phenomena are interrelated.
Tài liệu tham khảo
A. Junod, in Physical Properties of Type-II High-Temperature Superconductors, D. Ginzberg (World Scientific, Singapore, 1990).
K. R. Biagi, V. Kogan, and J. R. Clem, Phys. Rev. B 32, 7165 (1985).
S. Takahashi and M. Tachiki, Phys. Rev. B 33, 4620 (1986).
A. J. Schofield, Phys. Rev. B 52, 11733 (1995).
H. Won and K. Maki, Europhys. Lett. 30, 421 (1995).
G. E. Volovik, JETP Lett. 58, 469 (1993).
S. V. Zaitsev-Zotov, E. A. Protasov, and M. N. Khlopkin, Fiz. Tverd. Tela 26, 2933 (1984) [Sov. Phys. Solid State 26, 1772 (1984)].
E. Z. Meikhov and V. G. Shapiro, Sverkhprovodimost: Fiz., Khim., Tekh. 4, 1437 (1991).
A. P. Mackenzie, A. Carrington, S. D. Hughes, R. S. Liu, D. C. Sinclair, S. R. Julian, and G. G. Lonzarich, Phys. Rev. Lett. 71, 1238 (1993).
A. P. Mackenzie, S. R. Julian, G. G. Lonzarich, A. Carrington, S. D. Hughes, R. S. Liu, and D. C. Sinclair, J. Supercond. 7, 271 (1994).
M. S. Osofsky, R. J. Soulen, S. A. Wolf, J. M. Bioto, H. Racoto, J. S. Ousset, G. Coffe, S. Askenazy, P. Pari, and J. Bozovic, Phys. Rev. Lett. 71, 2315 (1993).
C. Escribe-Filippini, J. Marcus, M. Afronte, H. Racoto, J. M. Broto, J. C. Ousset, and S. Askenazy, Physica C 210, 133 (1993).
V. F. Gantmakher, L. A. Klinkova, N. V. Barkovskii, G. E. Tsydynzhapov, S. Wiegers, and A. K. Geim, Phys. Rev. B 54, 6133 (1996).
C. J. Gorter, H. Van Beelen, and R. De Bruyn Outboter, Phys. Lett. 8, 13 (1964).
K. Maki, Phys. Rev. 139, A702 (1965).
A. A. Abrikosov, Fundamentals of the Theory of Metals, North-Holland, Amsterdam (1988).
K. A. Moler, D. J. Baar, J. S. Urbach, Ruixing Liang, W. H. Hardy, A. Kapitulnik, Phys. Rev. Lett. 73, 2744 (1994).
K. A. Moler, D. J. Baar, Ruixing Liang, W. H. Hardy, A. Kapitulnik, J. Supercond. 8, 571 (1995).
R. A. Fisher, D. A. Wright, J. P. Emerson, B. F. Woodfield, N. E. Phillips, J. E. Gordon, S. F. Reklis, and E. M. McCarron, Physica C 252, 237 (1995).
B. Revaz, A. Junod, A. Mirmelstein, A. Erb, J.-Y. Genoud, and G. Triscone, Czech. J. Phys. 46, Suppl. S3, 1205 (1996).
A. M. Balbashev, D. A. Shulyatev, G. Kh. Panova, M. N. Khlopkin, N. A. Chernoplekov, A. A. Shikov, and A. V. Suetin, Physica C 256, 371 (1996).
F. C. Chou, J. H. Cho, and D. C. Johnston, Physica C 197, 303 (1992).
M. N. Khlopkin, N. A. Chernoplekov, and P. A. Cheremnykh, Preprint IAÉ-3549/10, Moscow (1982).
T. Tsuneto, J. Phys. Soc. Jpn. 57, 3499 (1988).
I. Ikeda, T. Ohmi, and T. Tsuneto, J. Phys. Soc. Jpn. 58, 1377 (1989).
N. R. Werthammer, E. Helfand, and P. C. Hohenberg, Phys. Rev. 147, 295 (1966).
G. Kh. Panova, A. A. Shikov, B. I. Savel’ev, A. P. Zhernov, N. V. Anshukova, A. I. Golovashkin, A. I. Ivanova, and A. P. Rusakov, Zh. Éksp. Teor. Fiz. 103, 605 (1993) [JETP 76, 302 (1993)].
A. S. Alexandrov, J. Ranninger, and S. Robaszkewicz, Phys. Rev. B 33, 4526 (1986).
A. S. Alexandrov and J. Ranninger, Solid State Commun. 81, 403 (1992).