Topal, U. | Alıkma, F. | Gulce Coker, E.

Article | 2013 | Journal of Superconductivity and Novel Magnetism26 ( 5 ) , pp.1831 - 1835

In this study a novel type of magnetometer capable of direct measurement of DC fields as low as 0.5 nT was described. The second harmonic voltage generated by polycrystalline superconductors inserted in AC and DC fields was used as sensor signal. The experiments have shown that a 0.5 nT DC field can be detectable by using Bi-2223 superconductors as the core material. The Bi-2223 reveals better sensitivity compared to the other high-Tc cuprates. Besides, the sensor works in a wide dynamical range (105 orders in magnitude), which increases its potential application areas. © Springer Science+Business Media New York 2012.

Topal, U. | Coker, E.G. | Alıkma, F. | Kolemen, U. | Uzun, O.

Article | 2014 | Journal of Superconductivity and Novel Magnetism27 ( 1 ) , pp.133 - 141

The second harmonic signal, which is generated by co-application of AC and DC fields to polycrystalline type-II superconductors, were analyzed in terms of the weak links and the critical current density. With this aim the YBa 2 Cu 3-x Zn x O 7-y (x=0, 0.01, 0.02, 0.03, 0.05, and 0.1) samples were synthesized in order to adjust intergranular couplings and thus the strength of weak links. The mechanical and magnetic measurements are in good agreement on that Zn doping reduces strength of the links between grains; however, contrary to the common expectations, it has no direct contribution to the 2nd harmonic signal strength. © 2013 Spr . . .inger Science+Business Media New York Daha fazlası Daha az

Gülce Çoker, E. | Kolemen, U. | Topal, U.

Article | 2014 | Journal of Superconductivity and Novel Magnetism28 ( 2 ) , pp.513 - 518

The effect of the intergranular couplings on the second harmonic of the fundamental signal, which is generated by co-application of DC and AC fields to a magnetic material having nonlinear magnetization, was investigated on B 2O3 doped YBaCuO superconductors. Physical and mechanical properties of B 2O3 doped YBaCuO superconductors were also analyzed to support electrical measurements. © 2014, Springer Science+Business Media New York.