高温超导体EuBa_2(Cu_(1-x)Fe_x)_3O_(7-y)的穆斯堡尔谱学新研究

New studies of EuBa_2(Cu_(1-x)Fe_x)_3O_(7-y)by Mossbauer spectroscopy

利用^(57)Fe和^(151)Eu穆斯堡尔效应对EuBa_2(Cu_(1-x)Fe_x)_3O_(7-y)高温超导体作了研究。在液氮温区,分别测量了样品中有和无电流通过时的^(57)Fe穆斯堡尔谱,结果表明取代了Cu(2)位置的Fe的同质异能位移和四极分裂与通过超导体的电流无关,而取代Cu(1)位置的Fe的穆斯堡尔谱参数则与电流有关。不同Fe含量样品的穆斯堡尔谱分析表明,超导电性和穆斯堡尔谱参数都与Fe的含量有关。

EuBa2 (Cu1-xFex)3O1-y has been investigated by the 57Fe and 151Eu Mossbauer spec-troscopy. The 77Fe Mossbauer spectra of EuBa2(Cu1-xFex)3O7-y have been measured around the superconducting transition temperature without or with a DC electric current of 0. 5 A. The results indicate that isomer shift (IS) and quadrupole splitting (QS) of the Fe atoms replacing the Cu(2) sites vary neither with the Fe content nor with electric current passing through the superconductor while both IS and QS of the Fe atoms replacing the Cud) sites vary with the Fe content. In addition, IS and QS of the Fe(D3) atoms replacing the Cu(1) sites are different before and after a small electric current passes thorough the superconductor at 80 K.