Two-dimensional incommensurate magnetic fluctuations in Sr2(Ru0.99Ti0.01)O4

Abstract

We investigate the imaginary part of the wave vector dependent dynamic spin susceptibility in Sr2(Ru0:99Ti0:01)O4 as a function of temperature using neutron scattering. At T = 5 K, two-dimensional incommensurate (IC) magnetic fluctuations are clearly observed around Qc = (0:3; 0:3;L) up to approximately 60 meV energy transfer. We find that the IC excitations disperse to ridges around the (; ) point. Below 50 K, the energy and temperature dependent excitations are well described by the phenomenological response function for a Fermi liquid system with a characteristic energy of 4.0(1) meV. Although the wave vector dependence of the IC magnetic fluctuations in Sr2(Ru0:99Ti0:01)O4 is similar to that in the Fermi liquid state of the parent compound, Sr2RuO4, the magnetic fluctuations are clearly suppressed by the Ti-doping.