Vortex Lattice in Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta} Well Above the First-Order Phase-Transition Boundary

Measurements of non-local in-plane resistance originating from transverse vortex-vortex correlations have been performed on a Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta} high-T_c superconductor in a magnetic field up to 9 T applied along the crystal c-axis. Our results demonstrate that a rigid vortex lattice does exist over a broad portion of the magnetic field -- temperature (H-T) phase diagram, well above the first-order transition boundary H_{FOT}(T). The results also provide evidence for the vortex lattice melting and vortex liquid decoupling phase transitions, occurring above the H_{FOT}(T).Comment: 14 pages, 10 figure

Evidence for internal field in graphite: A conduction electron spin resonance study

We report conduction electron spin resonance measurements performed on highly oriented pyrolitic graphite samples between 10 K and 300 K using S (f = 4 GHz), X (f = 9.4 GHz), and Q (f = 34.4 GHz) microwave bands for the external dc-magnetic field applied parallel (H || c) and perpendicular (H perp c) to the sample hexagonal c-axis. The results obtained in the H || c geometry are interpreted in terms of the presence of an effective internal ferromagnetic-like field Heff-int(T,H) that increases as the temperature decreases and the applied dc-magnetic field increases. We associate the occurrence of the Heff-int(T,H) with the field-induced metal-insulator transition in graphite and discuss its origin in the light of relevant theoretical models.Comment: 10 pages (tex), 5 figures (ps

Magnetic-Field-Driven Superconductor-Insulator-Type Transition in Graphite

A magnetic-field-driven transition from metallic- to semiconducting-type behavior in the basal-plane resistance takes place in highly oriented pyrolytic graphite at a field $H_c \sim 1~$kOe applied along the hexagonal c-axis. The analysis of the data reveals a striking similarity between this transition and that measured in thin-film superconductors and Si MOSFET's. However, in contrast to those materials, the transition in graphite is observable at almost two orders of magnitude higher temperatures.Comment: 4 Figure

Flux-line-lattice Melting In Bi2sr2ca2cu3o10

We have performed dc magnetization studies in the c-axis-oriented bulk Bi2Sr2Ca2Cu3O10 compound. The penetration depth λab(T) is extracted from reversible magnetization data M(H) taking into account fluctuations of the vortices. An ''irreversibility line'' is quantitatively compared with predictions of flux-line-lattice (FLL) melting models. The results strongly suggest that the ''irreversibility line'' near Tc is associated with melting of FLL caused by thermal fluctuations. © 1994 The American Physical Society.4921495149

High-temperature Local Superconductivity In Graphite And Graphite-sulfur Composites

Recently, the existence of localized superconducting domains at elevated temperatures has been demonstrated for both pure graphite and graphite-sulfur composites. In this note we report results of magnetization and magnetoresistance measurements which provide a further evidence for the local high-temperature superconductivity occurrence in these materials. © 2004 Elsevier B.V. All rights reserved.408-4101-47778Tanigaki, K., (1991) Nature, 352, p. 222Tang, Z.K., (2001) Science, 292, p. 2462Kopelevich, Y., (2000) J. Low Temp. Phys., 119, p. 691Kempa, H., (2002) Phys. Rev. B, 65, pp. 241101RKopelevich, Y., (2003) Phys. Rev. Lett., 90, p. 156402Das, D., Doniach, S., (2001) Phys. Rev. B, 64, p. 134511Feigel'man, M.V., (2001) Phys. Rev. Lett., 86, p. 1869Spivak, B., (2001) Phys. Rev. B, 64, p. 132502Ovchinnikov, Yu.N., (2001) Phys. Rev. B, 63, p. 064524Abrikosov, A.A., (2001) Phys. Rev. B, 63, p. 134518Da Silva, R.R., (2001) Phys. Rev. Lett., 87, p. 147001Yang, H.P., (2001) Chin. Phys. Lett., 18, p. 1648Moehlecke, S., (2002) Philos. Mag. B, 82, p. 1335González, J., (2001) Phys. Rev. B, 63, p. 13442

Conduction Electron Spin Resonance Evidence For Internal Field In Graphite

We report conduction electron spin resonance measurements performed on highly oriented pyrolitic graphite samples between 10 and 300K using S (ν = 4GHz), X (ν = 9.4GHz), and Q (ν = 34.4GHz) microwave bands for the external DC-magnetic field applied parallel (H ∥ c) and perpendicular (H ⊥c ) to the sample hexagonal c-axis. The results obtained in the H ∥ c geometry are interpreted in terms of the presence of an effective internal ferromagnetic-like field, H int eff(T, H), that increases as the temperature decreases and the applied DC-magnetic field increases. We associate the occurrence of the H int eff(T, H) with the field-induced metal-insulator transition in graphite and discuss its origin in the light of relevant theoretical models. © 2002 Elsevier Science B.V. All rights reserved.3201-4413415Xu, S., (1996) Phys. Rev. Lett., 76, p. 483Kopelevich, Y., (1999) Fiz. Tverd. Tela (St. Petersburg), 41, p. 2135Kopelevich, Y., (1999) Phys. Solid State, 41, p. 1959Kopelevich, Y., (2000) J. Low Temp. Phys., 119, p. 691Kempa, H., (2000) Solid State Commun., 115, p. 539Khveshchenko, D.V., (2001) Phys. Rev. Lett., 8720, p. 6401Dresselhaus, M.S., Dresselhaus, G., Sugihara, K., Spain, I.L., Graphite fibers and filaments Springer Series in Material Science, 5, pp. 179-188. , references therein, Springer, BerlinDresselhaus, M.S., (1981) Adv. Phys., 30, p. 139Sercheli, M.S., (2002) Solid State Commun., 121, p. 579Laughlin, R.B., (1998) Phys. Rev. Lett., 80, p. 5188Ferrer, E.J., cond-mat/010130

Thermomagnetic Flux-jump Instabilities And Second Magnetization Peak In Bi2sr2cacu2o8 High-tc Superconducting Crystals

Measurements of the magnetization hysteresis loop performed on Bi2Sr2CaCu2O8 high-Tc superconducting single crystals reveal the occurrence of pronounced jumps of the irreversible magnetization at T > 40 K. In this work we demonstrate their thermomagnetic origin. It is also shown that the low-field hollow in the magnetization hysteresis loops measured at T < 40 K and leading to the so-called "second magnetization peak," is the manifestation of a thermomagnetic instability effect. It is suggested that the plastic vortex motion triggers the magnetic instabilities.1163-4261276Higgins, M.J., Bhattacharya, S., (1996) Physica C, 257, p. 232Ertas, D., Nelson, D.R., (1996) Physica C, 272, p. 79Giller, D., Shaulov, A., Prozorov, R., Abulafia, Y., Wolfus, Y., Burlachkov, L., Yeshurun, Y., Greene, R.L., (1997) Phys. Rev. Lett., 79, p. 2542Vinokur, V., Khaykovich, B., Zeldov, E., Konczykowski, M., Doyle, R.A., Kes, P.H., (1998) Physica C, 295, p. 209Koch, C.C., Scarbrough, J.O., Kroeger, D.M., (1974) Phys. Rev. B, 9, p. 888Kartascheff, N., (1975) J. low Temp. Phys., 21, p. 203Modler, R., Gegenwart, P., Lang, M., Deppe, M., Weiden, M., Luhmann, T., Geibel, C., Takahashi, S., (1996) Phys. Rev. Lett., 76, p. 1292Dilley, N.R., Herrmann, J., Han, S.H., Maple, M.B., Spagna, S., Diederichs, J., Sager, R.E., (1996) Physica C, 265, p. 150Kopelevich, Y., Moehlecke, S., (1998) Phys. Rev. B, 58, p. 2834Khaykovich, B., Zeldov, E., Majer, D., Li, T.W., Kes, P.H., Konczykowski, M., (1996) Phys. Rev. Lett., 76, p. 2555Kopelevich, Y., Esquinazi, P., (1998) J. low Temp. Phys., 113, p. 1Esquinazi, P., Höhne, R., Kopelevich, Y., Pan, A., Ziese, M., (1999) Phys. and Mater. Sci. of Vortex States, , Flux Pinning, and Dynamics: Proc. of the NATO Adv. Study Inst., Kusadasi, Turkey, July 26-Aug. 8, 1998, edited by S. Bose and R. Kossowski, KluwerEsquinazi, P., Setzer, A., Fuchs, D., Kopelevich, Y., Zeldov, E., Assmann, C., to be publishedMints, R.G., Rakhmanov, A.L., (1981) Rev. Mod. Phys., 53, p. 551Wipf, S.L., (1991) Cryogenics, 31, p. 936Wu, W., Li, F., Jia, Y., Zhou, G., Qian, Y., Qin, Q., Zhang, Y., (1993) Physica C, 213, p. 133Kopelevich, Y., Makarov, V.V., Moehlecke, S., (1997) Physica C, 277, p. 225Wiesinger, H.P., Sauerzopf, F.M., Weber, H.W., (1992) Physica C, 203, p. 121Anders, S., Parthasarathy, R., Jaeger, H.M., Guptasarma, P., Hinks, D.G., Van Veen, R., (1998) Phys. Rev. B, 58, p. 6639Yeshurun, Y., Bontemps, N., Burlachkov, L., Kapitulnik, A., (1994) Phys. Rev. B, 49, p. 1548McHenry, M.E., Lessure, H.S., Maley, M.P., Coulter, J.Y., Tanaka, I., Kojima, H., (1992) Physica C, 190, p. 403Nideröst, M., Frassanito, R., Saalfrank, M., Mota, A.C., Blatter, G., Zavaritsky, V.N., Li, T.W., Kes, P.H., (1998) Phys. Rev. Lett., 81, p. 3231Kopylov, V.N., Koshelev, A.E., Schegolev, I.F., Togonidze, T.G., (1990) Physica C, 170, p. 291Burlachkov, L., (1993) Phys. Rev. B, 47, p. 8056Zeldov, E., Larkin, A.I., Geshkenbein, V.B., Konczykowski, M., Majer, D., Khaykovich, B., Vinokur, V.M., Shtrikman, H., (1994) Phys. Rev. Lett., 73, p. 1428Gough, C.E., (1987) Int. J. Mod. Phys. B, 1, p. 891Harrison, R.B., Pendrys, J.P., Wright, L.S., (1975) J. low Temp. Phys., 18, p. 113Niderst, M., Suter, A., Visani, P., Mota, A.C., Blatter, G., (1996) Phys. Rev. B, 53, p. 13Li, T.W., Menovsky, A.A., Franse, J.J.M., Kes, P.H., (1996) Physica C, 257, p. 179Jensen, H.J., Brass, A., Berlinsky, A.J., (1988) Phys. Rev. Lett., 60, p. 1676Nori, F., (1996) Science, 271, p. 1373Matsuda, T., Harada, K., Kasai, H., Kamimura, O., Tonomura, A., (1996) Science, 271, p. 1393Tsuboi, T., Hanaguri, T., Maeda, A., (1998) Phys. Rev. Lett., 80, p. 4550Forgan, E.M., Wylie, M.T., Lloyd, S., Lee, S.L., Cubitt, R., (1996) Czech. J. Phys., 46 (S3), p. 1571Pardo, F., De La Cruz, F., Gammel, P.L., Bucher, E., Bishop, D.J., (1998) Nature, 396, p. 348Koshelev, A.E., (1992) Physica C, 198, p. 371Koshelev, A.E., Vinokur, V.M., (1994) Phys. Rev. Lett., 73, p. 3580Mazilu, A., Safar, H., Lopez, D., Kwok, W.K., Crabtree, G.W., Guptasarma, P., Hinks, D.G., (1998) Phys. Rev. B, 58, p. 8913Doyle, R.A., Rycroft, S.F.W.R., Doyle, T.B., Zeldov, E., Tamegai, T., Ooi, S., (1998) Phys. Rev. B, 58, p. 135Fuchs, D.T., Doyle, R.A., Zeldov, E., Rycroft, S.F.W.R., Tamegai, T., Ooi, S., Rappaport, M.L., Myasoedov, Y., (1998) Phys. Rev. Lett., 81, p. 3944Wurlitzer, M., Mrowka, F., Esquinazi, P., Rogacki, K., Dabrowski, B., Zeldov, E., Tamegai, T., Ooi, S., (1996) Z. Phys. B, 101, p. 56

High-temperature Superconductivity In Graphite-sulfur Composites: Theoretical Analysis

Recently superconductivity in graphite-sulfur composites was experimentally observed. In this work we have analyzed the electronic structure changes associated with the presence of sulfur atoms in one and two dimensional graphite layers. We have considered ordered and disordered sulfur atoms distributions in many configurations. The density of states (DOS) of these structures were obtained using the negative factor counting (NFC) technique coupled to a tight-binding Hamiltonian (Hückel type). Our results indicate that the incorporation of sulfur atoms at edge graphite layers (changing their global geometric curvature and increasing the DOS at the Fermi level) might be in the origin of the graphite superconductivity.689127132Da Silva, R.R., Tores, J.H.S., Kopelevich, Y., (2001) Phys. Rev. Lett., 87, pp. 147001-147011González, J., Guinea, F., Vozmediano, M.A.H., (2001) Phys. Rev. B, 63, p. 134421Nagamatsu, J., Nakagawa, N., Muranaka, T., Zenitani, Y., Akimitsu, J., (2001) Nature (London), 410, p. 63Dean, P., Martin, J.L., (1960) Proc. Roy. Soc., A259, p. 409Ladik, J., Seel, M., Otto, P., Bakhshi, A.K., (1986) Chem. Phys., 108, p. 203Galvão, D.S., Dos Santos, D.A., Laks, B., De Melo, C.P., Caldas, M.J., (1989) Phys. Rev. Lett., 63, p. 786Lavarda, F.C., Dos Santos, M.C., Galvão, D.S., Laks, B., (1994) Phys. Rev. Lett., 73, p. 1267Galvão, D.S., Laks, B., Da Silva, R.R., Torres, J.H.S., Kopelevich, Y., to be publishe

Magnetic-field-driven Superconductor-insulator-type Transition In Graphite

A magnetic-field-driven transition from metallic- to semiconducting-type behavior in the basal-plane resistance takes place in highly oriented pyrolytic graphite at a field H c to approximately 1 kOe applied along the hexagonal c-axis. The analysis of the data reveals a striking similarity between this transition and that measured in thin-film superconductors and Si MOSFETs. However, in contrast to those materials, the transition in graphite is observable at almost two orders of magnitude higher temperatures.11510539542Simonian, D., Kravchenko, S.V., Sarachik, M.P., Pudalov, V.M., (1997) Phys. Rev. Lett., 79, p. 2304Kravchenko, S.V., (1998) Phys. Rev. B, 58, p. 3553Kravchenko, S.V., Klapwijk, T.M., (2000) Phys. Rev. Lett., 84, p. 2909Kravchenko, S.V., (1996) Phys. Rev. Lett., 77, p. 4938Yazdani, A., Kapitulnik, A., (1995) Phys. Rev. Lett., 74, p. 3037Markovic, N., Christiansen, C., Goldman, A.M., (1998) Phys. Rev. Lett., 81, p. 5217Phillips, P., Wan, Y., Martin, I., Knysh, S., Dalidovich, D., (1998) Nature, 395, p. 253Fischer, M.P.A., (1990) Phys. Rev. Lett., 65, p. 923Kopelevich, Y., Esquinazi, P., Torres, J.H.S., Moehlecke, S., (2000) J. Low Temp. Phys., 119, p. 691Kopelevich, Y., Lemanov, V.V., Moehlecke, S., Torres, J.H.S., (1999) Fizika Tverdogo Tela, 41, p. 2135(1999) Phys. Solid State, 41, p. 1959Dresselhaus, M.S., Dresselhaus, G., (1981) Adv. Phys., 30, p. 139Kelly, B.T., (1981) Physics of Graphite, Applied Science, p. 267. , London/New JerseyWilliamson, S.J., Foner, S., Dresselhaus, M.S., (1965) Phys. Rev., 140, pp. A1429Sharma, M.P., Johnson, L.G., McClure, J.W., (1974) Phys. Rev. B, 9, p. 2467Zhang, F.C., Rice, T.M., cond-mat/9708050 (unpublished)Rice, T.M., (1997) Nature, 389, p. 916Belitz, D., Kirkpatrick, T.R., (1998) Phys. Rev. B, 58, p. 8214Hebard, A.F., Paalanen, M.A., (1990) Phys. Rev. Lett., 65, p. 927Van Der Zant, H.S.J., (1992) Phys. Rev. Lett., 69, p. 2971Van Der Zant, H.S.J., (1996) Phys. Rev. B, 54, p. 10081Mason, N., Kapitulnik, A., (1999) Phys. Rev. Lett., 82, p. 5341Shimshoni, E., Auerbach, A., Kapitulnik, A., (1998) Phys. Rev. Lett., 80, p. 3352Vignale, G., Singwi, K.S., (1985) Phys. Rev. B, 31, p. 2729Richardson, C.F., Ashcroft, N.W., (1997) Phys. Rev. Lett., 78, p. 118Abrikosov, A.A., (1978) J. Less-Common Metals, 62, p. 451Young, D.P., Hall, D., Torelli, M.E., Fisk, Z., Sarrao, J.L., Thompson, J.D., Ott, H.-R., Zysler, R., (1999) Nature, 397, p. 412Murakami, S., Nagaosa, N., Sigrist, M., (1999) Phys. Rev. Lett., 82, p. 2939Kravchenko, S.V., Simonian, D., Mertes, K., Sarachik, M.P., Klapwijk, T.M., (1999) Phys. Rev. B, 59, p. 1274