In this work, we analyze the temperature dependencies of resistance and magnetoresistance for two RuSr2(Eu1.5Ce0.5)Cu2O10−δ ceramic samples, one of which was left in the as-prepared state while another one was oxygen saturated. The measurements on these samples were made soon after preparation and repeated after their long storage (10 years) in an ambient atmosphere when they lost most of their over-stoichiometric and part of stoichiometric oxygen. Having studied the widest possible range of oxygen concentrations, we are trying to clarify not only the questions of stability of superconducting state in ruthenocuprates, but also the interplay of various types of electronic hopping conductivity and superconductivity in granular magnetic material. Despite the significant progress made in understanding the properties of disordered conductors, the old question of mutual influence and competition between localization and superconductivity still not clear. Investigation of the properties of electron transport as it approaches the metal-insulator transition will be useful and important.

中文翻译：

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磁性超导体 RuSr2(Eu1.5Ce0.5)Cu2O10−δ 中跳跃电导率和超导性的相互作用

在这项工作中，我们分析了两个 RuSr2(Eu1.5Ce0.5)Cu2O10-δ 陶瓷样品的电阻和磁阻的温度依赖性，其中一个保持在制备状态，而另一个处于氧饱和状态。这些样品在制备后不久就进行了测量，并在它们在环境大气中长期储存（10 年）后重复测量，此时它们失去了大部分超化学计量氧和部分化学计量氧。在研究了尽可能广泛的氧浓度范围后，我们不仅试图澄清铜铜酸盐中超导状态的稳定性问题，而且还试图澄清粒状磁性材料中各种类型的电子跳跃电导率和超导性之间的相互作用。尽管在理解无序导体的特性方面取得了重大进展，定位和超导之间相互影响和竞争的老问题仍然不清楚。当电子传输接近金属-绝缘体转变时，研究电子传输的特性将是有用和重要的。