We observe the cation distribution, electronic structures, and magnetic properties of magnetically dead layers in typical ferromagnetic insulators CoFe2O4 and NiFe2O4 by XMCD. We reveal that the magnetically dead layer at the CoFe2O4 interface originates from various complex networks of superexchange interactions through the change in the cation distribution and electronic structure.

Y. K. Wakabayashi*, et al.
Physical Review B 96, 104410 (2017).
Physical Review Materials 2, 104416 (2018).