DYNAMICAL PROPERTIES OF CR-FE AMORPHOUS POWDERS OBTAINED FROM MECHANICAL MILLING

Mossbauer measurements have been performed in situ in the temperature range of 25 to 550-degrees-C for three Cr-Fe samples: Cr72Fe28 crystal line alloy (I), as-milled amorphous Cr65Fe35 powders made by mechanica l grinding (II) and the same powder annealed at 420-degrees-C for 2 h (III). The temperature dependence of isomer shifts for samples I and I II follows the variation predicted by the second-order Doppler effect, while for the sample II a deviation has been observed. The Debye temp eratures have been determined to be 420, 400 and 380 K for sample I, I II and II, respectively. A linear dependence on T3/2 of quadrupole spl itting of the annealed powder is observed.