Coercivity of Melt-Spun Gd$_{100-x}$Fe$_{x}$

We have measured the coercivity of melt-spun Gd$_{100-x}$Fe$_{x}$ (0$\le x\le $40) alloys over the temperature range 2 K$\le T\le $340 K. Previously performed structural measurements revealed that the system consists of crystalline hcp-Gd grains surrounded by a non-crystalline Gd or Gd-Fe phase composed of Gd$_{100-x'}$Fe$_{x'}$, where $x$'$>x$ is the iron concentration in the amorphous region. The two-phase structure is responsible for an unusual dependence of the coercivity on temperature in which non-zero coercivity is observed above the hcp-Gd $T_{c}$ with a peak near 320 K. The coercivity decreases as the hcp-Gd grains order, then increases with decreasing temperature. This behavior is explained by the presence of Fe-rich magnetically correlated regions.