Ferromagnetic and Antiferromagnetic Fluctuations ofπ−dItinerant Electrons Disclosed by Band-Selective NMR

We present a band-selective NMR method to probe the constituent electronic bands separately in the condensed molecular matter. This method is applied to an organic-inorganic $\pi -d$ hybrid metal, and its utility to give the static and dynamic spin susceptibilities for the constituent bands is demonstrated. The analysis of the results uncovers an exotic feature; the antiferromagnetic and ferromagnetic correlations are enhanced in separate bands in a single material. This finding provides a novel scope connecting the metal-insulator transitions in this system and the manganese oxides.