μ SR evidence of low frequency spin fluctuations in the AF phase of hole-doped NiO
INFM-Department of Physics "A. Volta", University of Pavia, 27100
Accepted: 21 August 1998
Published online: 15 January 1999
μSR measurements in the antiferromagnetic (AF) phase of Ni1-xLixO for 0≤x≤0.10 are reported. While in pure NiO the muon longitudinal depolarization rate is found almost temperature independent, in the Li-doped compounds broad maxima around 130 K are observed. These maxima are associated with the progressive freezing of the spin fluctuations of S=1/2 defects induced by the localization of the extra-holes. From the temperature dependence of and the stretched exponential form of the depolarization, insights on the distribution of correlation times for the fluctuating field at the muon site are derived.
PACS: 75.30.Hx – Magnetic impurity interactions / 75.40.Gb – Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.) / 76.75.+i – Muon spin rotation and relaxation
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999