Assessment of the Jahn-Teller effect in magnetostrictive (Ni,Zn) spinel ferrites by multiwavelength diffraction

This work aims to develop a better grasp on the cooperative Jahn-Teller (CJT) effect, to mitigate the detrimental effect of
magnetostriction on electromagnetic properties of soft ferrites. Mn3+ and Cu2+ ions in octahedral sites have a Jahn-Teller (JT) effect,
inducing structural deformation, breaking its symmetry to lift the degeneracy of eg orbitals. X-ray powder diffraction with a synchrotron
source could help observe lattice deformations in Ni-Zn-Cu and Ni-Zn-Mn ferrites. Measurements on the BM02-D2AM beamline will enable
to determine the Mn/Cu concentration threshold and strength of a CJT effect, leading to a better understanding of the role of symmetry
breaking on spin-orbit coupling.