Abstract
By inelastic neutron scattering, we have analyzed the magnetic correlations in the paramagnetic metallic region of the series CaSrRuO, . We find different contributions that correspond to two-dimensional ferromagnetic fluctuations and to fluctuations at incommensurate wave vectors , , and . These components constitute the measured response as a function of the Sr concentration , of the magnetic field, and of the temperature. A generic model is applicable to metallic CaSrRuO close to the Mott transition, in spite of their strongly varying physical properties. The amplitude, characteristic energy, and width of the incommensurate components vary only slightly as functions of , but the ferromagnetic component depends sensitively on concentration, temperature, and magnetic field. While ferromagnetic fluctuations are very strong in CaSrRuO with a low characteristic energy of 0.2 meV at K, they are strongly suppressed in CaSrRuO, but reappear upon the application of a magnetic field, and form a magnon mode above the metamagnetic transition. The inelastic neutron scattering results document how the competition between ferromagnetic and incommensurate antiferromagnetic instabilities governs the physics of this system.
3 More- Received 22 April 2010
DOI:https://doi.org/10.1103/PhysRevB.83.054429
©2011 American Physical Society