Funct. Mater. 2026; 33 (2): 154-159.
doi:https://doi.org/10.15407/fm33.02.154
Magnetoresistance of titanium-doped HTSC compounds YBaCuO
V.N. Karazin Kharkiv National University, Svobody Square,4, 61022 Kharkiv, Ukraine|The paper investigates the effect of titanium impurity on magnetoresistance in YBa2Cu3O7−δ ceramics in the region of transition to the superconducting state in a constant magnetic field up to 7 T. The reasons for the appearance of low-temperature "tails" (paracoherent transitions) on resistive transitions corresponding to different regimes of the phase state of vortex matter are discussed. At temperatures above the critical T>Tc, the temperature dependence of excess paraconductivity is satisfactorily described within the framework of the Aslamazov-Larkin theoretical model for the fluctuation conductivity of layered superconductors.
Abstract:
excess conductivity, YBa2Cu3O7−δ ceramics, titanium impurities, pinning, 2D-3D crossover, coherence length.
Keywords:
<p>1. J.G Bednorz and K.A. Muller. Possible High Tc Superconductivity in the Ba-La-Cu-O System. Z. Phys. B. 1986, V. 64, № 2, 189-193. http://dx.doi.org/10.1007/BF01303701.</p><p>2. T.A. Friedmann, J.P. Rice, J. Giapintzakis, D.M. Ginsberg. In-plane paraconductivity in a single crystal of superconducting. Phys. Rev. B,1989,39, 4258–4266. http://dx.doi.org/10.1103/PhysRevB.39.4258</p><p>3. R.V. Vovk, G.Ya. Khadzhai, I.L. Goulatis, A. Chroneos. Fluctuation conductivity of oxygen underdoped YBa2Cu3O7–δ single crystals Physica B: Condensed Matter,2014, Vol. 436, Pages 88–90. https://doi.org/10.1016/j.physb.2013.11.056</p><p>4. A. Solovjov, M. Tkachenko, R. Vovk, A. Chroneos. Fluctuation conductivity and pseudogap in HoYBa2Cu3O7–δ single crystals under pressure with transport current flowing under an angle 45° to the twin boundaries. Physica C,2014,501, 24 – 31. https://doi.org/10.1016/j.physc.2014.03.004</p><p>5. G. Blatter, M.V. Feigel’man, V.B. Geshkenbein, A.I. Larkin, V.M. Vinokur. Vortices in high-temperature superconductors. Rev. Mod. Phys. 1994, Vol. 66., 1125. https://doi.org/10.1103/RevModPhys.66.1125</p><p>6. R.V. Vovk, N.R. Vovk, O.V. Dobrovolskiy. Effect of Structural Relaxation on the In-Plane Electrical Resistance of Oxygen-Underdoped ReBaCuO (Re = Y, Ho) Single Crystals. J. Low Temp. Phys.,2014, 1–17. https://doi.org/10.1007/s10909-014-1121-9. </p><p>7. A.V. Bondarenko, V.A. Shklovskij, R.V. Vovk, M.A. Obolenskii, A.A. Prodan. Pinning and dynamics of magnetic flux in YBaCuO single crystals for vortex motion along twin boundaries. Low Temp. Phys. 1997,23, № 12, 962–967. https://doi.org/10.1063/1.593511</p><p>8. A.V. Bondarenko, V.A. Shklovskij, M.A. Obolenskii, R.V. Vovk, A.A. Prodan, M. Pissas, D. Niarchos, G. Kallias. Resistivity investigations of plastic vortex creep in YBa2 Cu3 O6.95 crystals. Phys. Rev. B. 1998, Vol. 58, № 5, 2445-2447. https://doi.org/10.1103/PhysRevB.58.2445</p><p>9. V.M. Pan, V.L. Svechnikov, V.F. Solovjov, V.F. Taborov, H.W. Zandbergen and J.G. Wen. YBa2Cu3O7–δ single-crystal microstructure related to transport critical current density. Supercond. Sci. Technol. 1992, V. 5, 707-711. https://doi.org/10.1088/0953-2048/5/12/002</p><p>10. R.V. Vovk, M.A. Obolenskii, A.A. Zavgorodniy, Z.F. Nazyrov, I.L. Goulatis, V.V. Kruglyak, A. Chroneos. Peculiarities of the relaxation processes in YBa2Cu3O7–δ (Re = Y, Ho) single crystals. Mod. Phys. Lett. B,2011, V. 25 № 27, 2131-2136. https://doi.org/10.1142/S0217984911027327</p><p>11. Z. Li, H. Wang, N. Yang, X. Jin, and L. Shen, J. Chin. Ceram. Soc. 18, 555 (1990).</p><p>12. S.V. Savich, A.V. Samoilov, R.V. Vovk, O.V. Dobrovolskiy, S.N. Kamchatna, Ya.V. Dolgopolova, O.A. Chernovol-Tkachenko. Excess conductivity and the pseudogap state in Hf-doped YBa2Cu3O7–δ ceramics. Mod. Phys. Lett. B,2016, Vol. 30, 1650034 (9 pages) https://doi.org/10.1142/S0217984916500342.</p><p>13. M.K. Wu, J.R. Ashburn, C.J. Torng, P.H. Hor, R.L. Meng, L. Gao, Z.J. Huang, Y.Q. Wang, and C.W. Chu. Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure. Phys. Rev. Lett. 1987, 58 (9), 908–910. https://doi.org/10.1103/PhysRevLett.58.908</p><p>14. B. Martinez, F. Sandiumenge, S. Pinol, N. Vilalta, J. Fontcuberta, X. Obradors. Aging of critical currents and irreversibility line in melt textured YBa2Cu3O7–δ. Appl. Phys. Lett. 1995,66, 772. https://doi.org/10.1063/1.114089</p><p>15. R.V. Vovk, N.R. Vovk, A.V. Samoilov, I.L. Goulatis, A. Chroneos. Effect of long aging on the resistivity properties of optimally doped YBa2Cu3O7–δ single crystals. Solid State Commun. 2013,170, 6-9. https://doi.org/10.1016/j.ssc.2013.07.011</p><p>16. T. Kemin, H. Meisheng, W. Yening. A superstructure in single crystals YBa2Cu3O7–δJ. Phys. Condens. Matter. 1989, V. 1, № 6, 1049-1054. https://doi.org/10.1088/0953-8984/1/6/002</p><p>17. R.V. Vovk, Z.F. Nazyrov, M.A. Obolenskii, I.L. Goulatis, A. Chroneos, V.M.P. Simoes. Effect of small oxygen deficiency on the para-coherent transition and 2D-3D crossover in untwinned YBa2Cu3O7–δ single crystals. J. Alloys Compd. 2011, Vol. 509, № 13, 4553-4556. https://doi.org/10.1016/j.jallcom.2011.01.102</p><p>18. R. Menegotto Costa, I.C. Riegel, A.R. Jurelo, J.L. Pimentel Jr. Coherence transition in polycrystalline Y0.95Tb0.05Ba2Cu3O7−δ superconductors. J. Magn. Magn. Mater. 2008,320, № 14, e493-e495. https://doi.org/10.1016/j.jmmm.2008.02.093</p><p>19. J.S. Kouvel, M.E. Fischer. Detailed Magnetic Behavior of Nickel Near its Curie Point. Phys. Rev. 1964,136, A1626. https://doi.org/10.1103/PhysRev.136.A1626</p><p>20. L.G. Aslamazov and A.I. Larkin. The influence of fluctuation pairing of electrons on the conductivity of normal metal. Phys. Lett. 1968,26, № 6, 238-239. https://doi.org/10.1016/0375-9601(68)90623-3</p><p>21. R.V. Vovk, N.R. Vovk, G.Ya. Khadzhai, O.V. Dobrovolskiy, Z.F. Nazyrov. Effect of high pressure on the fluctuation paraconductivity in Y0.95Pr0.05Ba2Cu3O7−δ single crystals. Curr. Appl. Phys. 2014,14, № 12, 1779-1782. https://doi.org/10.1016/j.cap.2014.10.002</p><p>22. J. Roa-Rojas, R. Menegotto Costa, P. Pureur, P.P. Prieto. Pairing transition, coherence transition, and the irreversibility line in granular GdBa2Cu3O7–δ Phys. Rev. B,2000,61, № 18, 12457-12462. https://doi.org/10.1103/PhysRevB.61.12457</p><p>23. R.V. Vovk, V.M. Gvozdikov, M.A. Obolenskii, Z.F. Nazyrov, V.V. Kruglyak. Magnetoresistance and Intrinsic Pinning of Vortices in the Untwinned YBa2Cu3O7–δ Single Crystals with Optimal Oxygen Content and a Small Deviation from the Oxygen Stoichiometry. Acta Phys. Pol. A,2012, Vol. 121, № 5-6, 1191-1194. https://doi.org/10.12693/APhysPolA.121.1191</p><p>24. W.K. Kwok, S. Fleshler, U. Welp, V.M. Vinokur, J. Downey, G.W. Crabtree, M.M. Miller. Vortex lattice melting in untwinned and twinned single crystals of YBa2Cu3O7–δ. Phys. Rev. Lett. 1992,69, 3370. https://doi.org/10.1103/PhysRevLett.69.3370,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,