(i.)
Defects/strain influenced magnetic properties and inverse of surface spin
canting effect in single domain CoFe2O4 nanoparticles
Variation of saturation
magnetization with the size of the CFO nanoparticles. Curve (A) is the
simulated curve that presents a variation of Ms with size when only the effect of intrinsic strain is taken into
account, curve (B) is the simulated curve that presents the variation of Ms with size when the presence of a dead layer is taken into account
and –•– are the
experimentally observed points.
(ii) Tuning of optical bandgap and
magnetization of CoFe2O4 thin films
We
demonstrated that the optical bandgap and the saturation magnetization of CFO
films could be modified by controlling the annealing temperature of CFO films.
We have correlated these changes in the optical and magnetic properties of the
post annealed films at different temperatures with the redistribution of Co2+
among tetrahedral and octahedral sites and explained it quantitatively using
the Raman peak intensity ratio, which is a novel approach.
(iii.)
Tailoring the optical bandgap and magnetization of cobalt ferrite thin films
through controlled zinc doping
We have demonstrated that the controlled doping of
zinc can modify the optical bandgap and the saturation magnetization of CFO
films without changing the crystal structure of the cobalt ferrite (CFO) thin
films. This change in the optical and magnetic properties is attributed to the
change in the relative population of the Co2+ at the tetrahedral and octahedral
sites. Raman study confirms the decrease in the population of Co2+ at
tetrahedral sites with controlled Zn doping in CFO thin films.
