Evolution of superconducting and normal state properties of YBa2Cu3O7−y thick films under 200MeV Ag ion irradiation

• Published in: Physica. C, Superconductivity Vol. 480; pp. 98 - 101
• Main Authors: Biswal, R., Behera, D., Kanjilal, D., Satyam, P.V., Mishra, N.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2012
• Subjects: Oxygen ordering; Superconducting thick film; Swift heavy ion irradiation; Swift heavy ion irradiation; Oxygen ordering; Superconducting thick film
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2012.05.012

► 200MeV Ag ion irradiation was done on superconducting YBa2Cu3O7−y thick films. ► The fluence was varied from 1×1011 ionscm−2 to 5×1012 ionscm−2 in four steps. ► For 1×1011 ions cm−2, an increase in Tc and decrease of resistivity were observed. ► The increase of Tc is due to the oxygen ordering in CuO chain of YBa2Cu3O7−y films. ► The ordering is performed by ion induced secondary electrons at room temperature. Temperature dependent resistivity of YBa2Cu3O7−y (YBCO) thick films irradiated with 200MeV Ag ions has been investigated. The YBCO thick films were prepared by solid state diffusion reaction technique. In contrast to the general perception that the energetic ion induces defects and disorders, which lead to decrease of Tc and increase of normal state resistivity in a superconductor, 200MeV Ag ions in the present case led to an increase in Tc and decrease in normal state resistivity at low ion fluence (1011 ions cm−2) in YBCO. At this fluence, the electronic energy loss, Se induced amorphous ion tracks are well separated from each other and hence are not expected to influence the Tc. The observed changes in transport properties is explained as being caused by irradiation-induced chain oxygen ordering of the oxygen defects in the CuO chains. Subsequent increase of irradiation fluence leads to decrease of Tc and increase of normal state resistivity.