Muon spectroscopy of a frozen ferrofluid

M. Balasoiu^{1, 2} - V. L. Aksenov^{1, 3} - D. Bica⁴ - V. N. Duginov¹ - K .I. Gritsaj¹ - T. Mamedov¹ - V. Tripadus² - L. Vekas⁴ - V. A. Zhukov¹

¹ Joint Institute for Nuclear Research, Dubna, Russia
² Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
³ Russian Research Centre, Kurchatov Institute, Moscow, Russia
⁴ Center for Fundamental and Advanced Technical Research, Timisoara, Romania

Abstract
The behavior of the muons stopped in a magnetite D₂O-based ferrofluid in the temperature range of 114-300 K, both in zero field and in a transversal field applied to the muon-spin direction, was investigated. A considerable relaxation of the muon polarization was observed in both cases. Some irregularities of the behaviour of the polarization amplitude and the relaxation rate were observed in zero field at 240-255 K. The dispersion of the magnetic field at the muons in the sample, δB ≈ 20 G, was obtained. Figs 3, Refs 25.