Contribution to the Study of Elementary Magnetic Excitations in the \(\left[ {{\text{Fe}}/{\text{Pt}}} \right]\) Superlattice

The thickness of the magnetic ( \({t_{\textrm{Fe}}}\) $t_{\text{Fe}}$ ) and non-magnetic ( \({t_{\textrm{Pt}}}\) $t_{\text{Pt}}$ ) layers have an effect on the magnetic exchange anisotropy property, which is related to the evolution of the mixture’s magnetization, as we will explore in this study. We concentrate on the existence of two distinct “classical” and “quantum” magnons populations that were both generated at \({(T\simeq \frac{T \text{c}}{3})}\) $(T\simeq \frac{T\text{c}}{3})$ and were consistently connected to the occurrence of a spin reorientation transition (SRT). The existence of this “mixture” is confirmed by the extremely high agreement between the calculated results \(M_{cal}^ z (T, t, h)\) $M_{\mathit{cal}}^z(T,t,h)$ and the observed values \(M_{exp}^ z (T, t, h)\) $M_{\mathit{exp}}^z(T,t,h)$ . Using this information, we were able to determine the values of the various properties of the studied system, \(\mathrm {(Fe/Pt)}\) $(\mathrm{Fe}/\mathrm{Pt})$ , including the exchange integrals \((J_\Vert , J_\perp )\) $(J_{\Vert },J_{\perp })$ , the surface anisotropy \(\alpha\) $\alpha$ , the magnetocrystalline anisotropy \(\Delta\) $\mathrm{\Delta }$ , the critical transition temperature \(T_c\) $T_c$ , the magnon creation gap \(E_g\) $E_g$ , the lifetime of the created magnons \(\tau\) $\tau$ and the spin constant \(B_{3/2}\) $B_{3/2}$ .