super(99,101)Ru NMR study of EuSr sub(2)RuCu sub(2)O sub(8)

• Published in: Physica. C, Superconductivity Vol. 378-381; pp. 399 - 403
• Main Authors: Sakai, Hironori, Osawa, Naoki, Yoshimura, Kazuyoshi, Fang, Minghu, Kosuge, Koji
• Format: Journal Article
• Language: English
• Published: 01.10.2002
• ISSN: 0921-4534

The copper-ruthenium oxide, EuSr sub(2)RuCu sub(2)O sub(8) has been studied by means of nuclear magnetic resonance (NMR) and nuclear spin-lattice relaxation rate (T super(-1) sub(1)) measurements. This compound shows the ferromagnetic-like transition at T sub(M) [similar to] 130 K and the superconducting transition at T super(onset) sub(c) [similar to] 30 K. super(99,101)Ru NMR signals under zero applied field have been observed at high frequencies around 60 MHz and around 130 MHz, both of which could be identified as ferromagnetic resonances even below T super(onset) sub(c). These frequency-swept spectra around 60 MHz and around 130 MHz are ascribed to super(99,101)Ru nuclei of Ru super(4+) (S = 1) and to those of Ru super(5+) (S = 3/2), respectively. The nuclear spin-lattice relaxation rate T super(-1) sub(1) for super(101)Ru nuclei decreases just below T super(onset) sub(c) due to the formation of a superconducting gap. Our NMR results are supported microscopically that coexistence of the ferromagnetism and superconductivity is realized in this compound. copyright 2002 Elsevier Science B.V. All rights reserved.