CHI('') PEAK MEASUREMENTS IN CHOSEN CHROMATE WITH NONCOLLINEAR SPIN STRUCTURE

The use of AC inductance techniques to measure the AC absorption (chi' ') in chosen chromate with noncollinear spin structure is discussed. T he single sharp peaks in chi'' versus temperature are typically seen f or good samples of Zn1-xAxCr2Se4, where A = Cu or Ga2/3. The out-of-ph ase (imaginary, chi'') peak is discussed in the framework of different types of the relaxation processes causing a dissipation of energy of the H(AC) field. It turned out that substitution of the Zn2+ ions by C u1+ or Ga3+ ions caused an increase of losses, which has well been sho wn in the characteristics of the loss factor versus temperature. For A = Cu0.11 composition, it is postulated that relaxation losses are acc ompanied also by eddy currents.