Manik Kuila | Searcharxiv

arXiv2021

Robust perpendicular magnetic anisotropy in Ce substituted yttrium iron garnet epitaxial thin films

Cerium substituted yttrium iron garnet (Ce:YIG) epitaxial thin films are prepared on gadolinium gallium garnet (GGG) substrate with pulsed laser deposition (PLD). It is observed that the films grown on GGG(111) substrate exhibit perpendicular magnetic anisotropy (PMA) as compared to films grown on GGG(100) substrate. The developed PMA is confirmed from magneto-optical Kerr effect, bulk magnetization and ferromagnetic resonance measurements. Further, the magnetic bubble domains are observed in the films exhibiting PMA. The observations are explained in terms of the growth direction of Ce:YIG films and the interplay of various magnetic anisotropy terms. The observed PMA is found to be tunable with thickness of the film and a remarkable temperature stability of the PMA is observed in all the studied films of Ce:YIG deposited on GGG(111) substrate.

cond-mat.mtrl-sci↗

arXiv2021

Sublattice spin reversal and field induced $Fe^{3+}$ spin-canting across the magnetic compensation temperature in $Y_{1.5}Gd_{1.5}Fe_{5}O_{12}$ rare-earth iron garnet

In the present work $Fe^{3+}$ 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) by means of in-field $^{57}Fe$ M$\ddot{o}$ssbauer spectroscopy measurements. Corroborating in-field $^{57}Fe$ M$\ddot{o}$ssbauer measurements, both $Fe^{3+}$ & $Gd^{3+}$ sublattice spin reversal has also been manifested with x-ray magnetic circular dichroism (XMCD) measurement in hard x-ray region. Moreover 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 signal is observed to consist of additional spectral features, those are identified from $Gd^{3+}$ ($Fe^{3+}$) magnetic ordering, enabling us the extraction of both the sublattices ($Fe^{3+}$ & $Gd^{3+}$) information from a single edge analysis. The evolution of the magnetic moments as a function of temperature for both magnetic sublattices extracted either at the Fe K- or Gd $L_3$-edge agree quite well with values that are extracted from bulk magnetization data of YGdIG and YIG ($Y_{3}Fe_{5}O_{12}$). These measurements pave new avenues to investigate how the magnetic behavior of such complex system acts across the compensation point.

cond-mat.mtrl-sci↗