Abstrakt: |
Abstract: Pulsed NMR measurements were performed on [Tm1 (Tm2)]90+x Zr10−x (Tm=Fe, Co, Ni) amorphous alloys utilizing a newly developed low temperature wide band probehead-preamplifier system. A 11,6 T broad57Fe hyperfine field distribution around the average of 23.6 T together with a less intensive peak around 11 T has been found in Fe90.6Zr9.4, in excellent agreement with Mssbauer studies. A rather flat distribution around the average value of 14.8 T characterizes the transferred hyperfine field at the Zr sites in the same alloy. Both features provide strong evidence for a broad range of exchange interactions and variations in the spin density at the Fe sites in this material. A much narrower and symmetrical distribution at the Zr sites around 10 T in Co90Zr10 is evidence of the higher magnetic homogeneity of this alloy as compared to Fe90Zr10. In Fe60Ni30Zr10, in addition to the57Fe signal, a contribution from61Ni nuclei could be separated, corresponding to an average hyperfine field value of 15.3 T. |