Sublattice spin reversal and field induced Fe3+spin-canting across the magnetic compensation temperature in Y1.5Gd1.5Fe5O12rare-earth iron garnet.

ABSTRACT

In the present work Fe3+sublattice spin reversal and Fe3+spin-canting across the magnetic compensation temperature (TComp) are demonstrated in polycrystalline Y1.5Gd1.5Fe5O12(YGdIG) by means of in-field57FeMössbauer spectroscopy measurements. Corroborating in-field57FeMössbauer measurements, both Fe3+& Gd3+sublattice spin reversal has also been manifested in hard x-ray magnetic circular dichroism (XMCD) measurements. From in-field57FeMössbauer measurements, estimation and analysis of effective internal hyperfine field (Heff), relative intensity of absorption lines in a sextet elucidated unambiguously the signatures of Fe3+spin reversal and field induced spin-canting of Fe3+sublattices across TComp. Gd L3-edge XMCD signal is observed to consist of an additional spectral feature, identified as Fe3+magnetic contribution to XMCD spectra of Gd L3-edge, enabling us the extraction of both the sublattices (Fe3+& Gd3+) information from a single absorption edge analysis. The evolution of the XMCD amplitudes, which is proportional to magnetic moments, as a function of temperature for both magnetic sublattices extracted at the Gd L3-edge reasonably match with values that are extracted from bulk magnetization data of YGdIG and YIG (Y3Fe5O12) and corresponding Fe K-edge XMCD amplitudes for Fe contribution. These measurements pave new avenues to investigate how the magnetic behavior of such complex system acts across the compensation point.