  We have investigated the coupling of lattice with spin via strain
interactions in the CoFe2O4/PMN-PT composite system. X-ray diffraction and
Raman spectroscopic studies illustrate a remarkable modification in
CoFe2O4lattice across Curie temperature (450 K) of PMN-PT. Subsequently,
CoFe2O4/PMN-PT composite reveals a sudden drop in magnetic moment across Tc of
PMN-PT (450 K). However,theindependent CoFe2O4phasedisplaystypical
ferromagnetic behaviour across this temperature. These findings establish
spin-lattice coupling owing to th interfacial strain transfer between CoFe2O4
and PMN-PT in composite. The strain intractions leads to magneto-electric
coupling, evidenced by measuring magentization and magneto-electric coefficient
for the electric field poled and unploed CoFe2O4/PMN-PT composite samples.
X-ray magnetic circular dichroism (XMCD) analysis establishes that the cation
(Fe3+/Co2+) redistribution occurs on tetrahedral and octahedral site in the
electrically poled CoFe2O4/PMN-PT composite, confirming the coupling between
magnetic and electric ordering in the composite. The magneto-electric coupling
coefficient alpha vs dc magnetic field curves revealed hysteretic behavior and
enhanced {\alpha} values after electric poling, which originates from the
strain induced modifications in the magnetic domains configuration of composite
in the poled samples. These findings suggest that the existence of spin lattice
coupling may leads to the mechanism of strong magneto-electric effects via
strain interactions in CoFe2O4/PMN-PT composite.

Materials Science