Magnetic disorder in the Cu0.995Fe0.005O solid solution

The magnetic hyperfine field, measured by Mossbauer spectroscopy. of a Cu(F e)O solid solution displays a spin-glass-like behaviour that undergoes two transitions. The samples were produced by a 48 h ball-milling and 40 h succ essive annealing treatments at 650, 700 and 800 K with 0.25 mol% of alpha-( Fe2O3)-Fe-57 and CuO. The signal shows a magnetic splitting that develops a t temperatures lower than ca. 150 K. The measured distribution of hyperfine fields broadens at lower temperatures and its behaviour down to 15 K extra polates to a saturation field of approximate to 29 T. The second transition takes place at temperatures between 4.2 and 15 K. The observed magnetic be haviour is interpreted in terms of magnetic disorder and canted local state s of the system of magnetic moments. (C) 1999 Elsevier Science B.V. All rig hts reserved.