Sublattice spin reversal and field induced $Fe^{3+}$ spin-canting across the magnetic compensation in rare-earth iron garnets

In the present work $Fe^{3+}$ & $Gd^{3+}$ sublattice spin reversal and $Fe^{3+}$ spin-canting across the magnetic compensation temperature ($T_{Comp}$) are demonstrated in polycrystalline $Y_{1.5}Gd_{1.5}Fe_{5}O_{12}$ (YGdIG) with in-field $^{57}Fe$ M$\ddot{o}$ssbauer spectroscopy and hard x-ray magnetic circular dichroism (XMCD) measurements. From in-field $^{57}Fe$ M$\ddot{o}$ssbauer measurements, estimation and analysis of effective internal hyperfine field ($H_{eff}$), relative intensity of absorption lines in a sextet elucidated unambiguously the signatures of $Fe^{3+}$ spin reversal, their continuous transition and field induced spin-canting of $Fe^{3+}$ sublattices across $T_{Comp}$. Further, Fe K- (Gd $L_{3}$) edge XMCD data is observed to consist the spectral features from $Gd^{3+}$ ($Fe^{3+}$) magnetic ordering enabling the extraction of both the sublattice ($Fe^{3+}$ & $Gd^{3+}$) information from a single edge XMCD analysis. The observed magnetic moment variation of both the sublattices extracted from either Fe K- or Gd $L_{3}$ edge XMCD data is observed to follow the trend of bulk magnetization.