Electron irradiation effects in doped high temperature superconductors YBa2Cu3−x MxOy (M = Fe, Ni; x=0; x=0:01)

Abstract

Abstract:The influence of irradiation by electrons with an energy of 8 MeV, at dose intervals between 10 13 and 2×10 18 el/cm 2 , on the properties of impurity doped, high-temperature superconductor YBa 2 Cu 3− M O (M = Fe, Ni; = 0; = 0 01) ceramics has been studied. It has been established that, as the irradiation dose is increased, the onset temperature of the transition to the superconducting state (T ), and the intergranular weak link coupling temperature between granules (T J ), exhibit an oscillation around their initial values of approximately about 1-1.5 K. This oscillation indicates that the process of radiation defect formation in HTSC occurs in multiple stages. It was also found that the critical current (J ) decreases with an increase of the irradiation dose, and exhibits a local minimum at a dose of 8 × 10 16 el/cm 2 coinciding with minima for T and T J at this dose. It was found that the introduction of Fe atoms to the ceramic decreases T J , while introducing Ni atoms decreases both T and T J ; it is suggested that this is a result of Ni substitution of Cu both in Cu2 plane sites and Cu1 chain sites. The introduction of Ni causes a large change in the intergranular critical current density, J . A critical irradiation dose is obtained (2 × 10 18 ) after which all HTSC parameters strongly decrease, i. e. the superconductivity of HTSC is destroyed. 74.62.Dh, 74.72Bk, 74.25Ha, 74.25Sv PACS (2008):

Oxygen Plasma Effects on Zero Resistance Behavior of Yb,Er‐doped YBCO (123) Based Superconductors

“…[29][30][31][32][33] (ii) Changing the composition and/or structure of the superconductors by the use of radiation of different energy content and nature realized with very different techniques. [34][35][36][37][38][39][40][41][42][43][44] (iii) Changing the composition and/or structure of the superconductors by annealing or post-annealing in different atmospheres. [45][46][47] With the benchmarks, established by other groups in mind it was aimed to generate a lead, mercury, and thallium free superconductor, which retains its zero resistance behavior up to nearly 100 K. In order to shift the critical transition temperatures of YBCO superconductors to higher values, yttrium was partially replaced by ytterbium and erbium.…”

“…The irradiation experiments includes diverse radiation, for instance electromagnetic radiation with short wavelengths like Y-irradiation, [41] X-ray irradiation, [70,71] radiation in the visible optical spectrum, [35,36,44] or radiation with wavelengths in the NIR or IR [72,73] region. In addition scientists carried out particle irradiation using beams consisting of electrons, [42,[74][75][76] ions, [37,74,[77][78][79] protons, [80,81] and neutrons. [75,82] Within the group of particle irradiation experiments the results achieved with oxygen ion bombardment (ion etching) seem to be the most promising ones.…”

Effect of Direct Transport Current and Heat Treatment on Resistive Properties of Bismuth-Based Ceramic High-Temperature Superconducting Oxides of Various Compositions

“…Bulk ceramic (and especially bismuth-based) HTS systems are convenient objects for this purpose, because they contain a wide range of various granules linked by weak bonds of different energies. Here, the energy and character of these bonds in a sample can be modified by changing its impurity composition, bulk density as well as by applying external magnetic, electrical, radiation fields, and various types of heat treatment [11][12][13][14][15][16][17][18][19][20]. On the other hand, the choice of such complex HTS compound as bismuth ceramics is justified by the fact that here -as distinct from yttrium compounds -the effect of thermo-magnetic prehistory (hysteresis phenomena) on the resistive transition is relatively insignificant at low transport current densities [2].…”

“…When the HTS materials are irradiated by various high-energy particles at low doses, T C also exhibits nonmonotonic behavior depending on irradiation dose [16][17][18][19][20]. A typical granular HTS sample contains unstable phases in the form of various weak Josephson links, and each of them responds differently to external factors [16].…”