Structural inhomogeneity effects in resistive superconducting transitions of the magnetic superconductor RuSr₂(Gd_1.5Ce_0.5)Cu₂O_10−δ

Hysteresis and stepwise structure in MR curves of granular superconducting ruthenocuprates RuSr2(Gd1.5Ce0.5)Cu2O10−δ

“…Polycrystalline structure of the ruthenocuprates determines the pronounced granular superconductivity effects in these compounds [8,9,10,11]. The results found are quite similar to those known for granular high-T c superconductors, and can be considered in a similar way.…”

“…It is associated with the reduction of the intragrain superconducting gap ∆(T ) in an applied magnetic field, that causes an increase in the unpaired quasi-particle density and corresponding decrease in resistance [24]. Although the intragrain upper critical field is found to be very large in the Ru1222-Gd compound [10], close enough to T c0 , the field applied in this study (up to 1.6 T) is quite enough to suppress intragrain superconductivity. It is seen in Fig.…”

“…The Gd doped sample RuSr 2 Gd 1.5 Ce 0.5 Cu 2 O 10−δ (Ru1222-Gd) has been studied. The study is to some degree a continuation of our previous studies [10,11] of granular superconductivity effects in the Ru1222-Gd. We will describe here some new results not mentioned in previous articles [10,11].…”

“…The study is to some degree a continuation of our previous studies [10,11] of granular superconductivity effects in the Ru1222-Gd. We will describe here some new results not mentioned in previous articles [10,11]. In particular, a stepwise structure in MR curves taken with increasing and decreasing field has been found and discussed.…”

“…The intergrain contacts of any grain can be of different types [13]. Granular superconductors have a widened (in contrast to that in homogeneous superconductors) temperature range of resistive transition to the superconducting state, with a "shouldered" form of resistive curves R(T ), which is also a feature of the ruthenocuprates [8,9,10,11]. The shouldered form of the resistive transition reflects the inhomogeneous state of a granular superconductor.…”