Structure of Correlations in Fe99Zr10 Spin Glass

There are various representations for the long time evolution and the dynamics of spin glasses, but a coherent, overall accepted real space description remains lacking. Small-Angle Neutron Scattering measurements reveal the long range spin-spin correlations from which the correlation length as a function of the temperature, time or magnetic field can be deduced. The scattering of the amorphous Fe90Zr10 alloy during zero magnetic field cooling arises from long range correlations described by a Lorentzian function and scattering from spin clusters. From the temperature dependence of the correlation length two transitions are observed without, however, the correlation length to diverge. The application of magnetic field suppresses the transitions. The experimental findings are discussed in conjunction with different theoretical models.