The local structure transformation in Nd1.85Ce0.15CuO4 films irradiated by He+ ions: polarized EXAFS study

✍ Scribed by A.Yu. Ignatov; A.P. Menushenkov; A.A. Ivanov; D.I. Kochubey

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 789 KB
• Volume: 234
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90056-6

✦ Synopsis

Copper K edge polarized EXAFS data of Nd,.ssCeo.15Cu04 films have indicated that He+ ion irradiation induces radiative defects in the Nd(Ce)-O(2) structures. Static disorder with typical displacement from the primary plane site up to 0.1 8, for the 0( 2) environments was observed. A cumulant treatment has been applied for space-disorder analyses of the Nd(Ce) site in irradiated samples. We estimated the C,, C,, C, expansion coefficients and found that the cumulant series of Cu-Nd(Ce) distance distribution is convergent at the range of photoelectron wave vector k=4-11 A-' and a radiation fluence @= lOI cm-*. We have not found any local changes in the CuOz plane structure after irradiation. The data obtained and superconductivity deterioration in the irradiated compounds point out the essential role of the ordering in the Nd (Ce)-0 (2) complexes for superconductivity in the Cu02 planes.