Ferromagnetic Correlations in Ca-Doped Sr2RuO4: 87Sr NMR Study.

Abstract Magnetic properties on Sr2-xCaxRuO4 have been investigated by a microscopic probe of 87Sr-NMR in order to understand the magnetic character on spin-triplet superconductor of Sr2RuO4, which has multibands on the Fermi surface. With substituting Ca for Sr which gives rise to crystal distortion, the Knight shift (K) and the nuclear spin-lattice relaxation rate divided by temperature (1/T1T) increases progressively up to x=1.5. The Korringa relation from K and 1/T1T becomes smaller, indicative of development of ferromagnetic fluctuations with increasing Ca content. This suggests that the q-independent spin fluctuations originating from the 2-dimensional ? band are changed to the ferromagnetic ones by the Ca doping. [ABSTRACT FROM AUTHOR]