Ring uniformity in amorphous photonic band gap materials

Critical behavior in the ferromagnet

“…In addition to the magnetic phase transition at Curie temperature, there is a cusp near 70 K, which is clearly shown in the dρ/dT curve. The cusp is observed in Mn 5 Ge 3 thin films or nanostructures but never observed in bulk crystal before [32][33][34]. For the first time, we observed it in the single crystal.…”

“…For the first time, we observed it in the single crystal. Generally, the emergence of the cusp is considered as a signal of magnetic transition in previous reports [32][33][34]. The discussion can be found in the last part of this paper.…”

“…In the early studies about the Mn 5 Ge 3 films or nanostructure [32][33][34], just due to the observed cusp near 70 K in the dρ/dT curves they suggest that it may be a possible magnetic transition between collinear and noncollinear spin configurations, like in Mn 5 Si 3 . Hence, the transition around 70 K do need to be further determined.…”

“…The DFT calculations [51] also point out that both the rigid model and the relaxed model do provide negative exchange constant, which cannot be ignored. The coexistence of AFM and FM coupling probably contributes to noncollinear spin configuration [34].…”