The higher
magnetic moments, in case of x = 0.03 Fe and Ni doped
samples, are may be due to the indirect exchange
interaction among TM ions, mediated by O ions. As the
TM ion concentration increases, the nearby two or more
TM ions are expected to come closer sufficiently. If such
TM atom pairs are present in the SnO2 lattice, the well
known super‐exchange interaction is expected between
them. The super‐exchange interaction may lead to the
anti‐ferromagnetic type interaction among neighbouring
TM‐ions, leading to the observed decrease in magnetic
moment with increasing TM concentration. The decrease
in the magnetic moments of Fe and Ni ions, with
increasing their doping concentrations, is consistent with
our previously reported results of Co‐doped SnO2
nanoparticles [17], where we have observed a little
reduction in the magnetic moments of Co ions, with
increasing their doping concentrations. Therefore, the
observed room temperature ferromagnetism in
chemically synthesized Fe and Ni doped SnO2 samples is
intrinsic to the material and confirm the formation of
SnO2 based DMS systems.