Critical dynamics of aufe reentrant ferromagnets close to the percolation threshold

✍ Scribed by C. Pappas; C. Lartigue; M. Alba; F. Mezei

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 226 KB
• Volume: 165-166
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/s0921-4526(90)80945-f

✦ Synopsis

We present inelastic neutron scattering data on critical dynamics of hFe 18% and 16% disordered ferromagnets. The concentrations of samples were close to the critical value (xc N 15.5%) where ferromagnetism disappears and spin-glass sets in. The value of the dynamic critical exponent z for &aFe 18% (z k 2.3) is close to that of a BD Heisenberg ferromagnet, i.e. is not affected by disorder. On the other hand, we found z N 1.8 for bFe 16%. This drastic decrease of the dynamic critical exponent, for a small change of the Fe concentration, suggests an influence of disorder on critical dynamics.