  We have observed enhancement and shift in the spin reorientation transition
temperature as a consequence of coexistence of orthorhombic and hexagonal
phases and higher aspect ratio in nanoscale LuFeO3. Nanoparticles and
nanofibers of LuFeO3 are considered for this work. Nanoparticles have 75 %
orthorhombic phase and 25 % hexagonal phase, while nanofibers have 23%
orthorhombic phase and 77%-hexagonal phase. Larger aspect ratio in case of
nanofibers is seen to help strain-stabilize the hexagonal phase in the
material. Magnetic measurements show significant difference in the magnetic
behavior and spin reorientation temperature; 183K for the nanoparticle case and
150K for the case of nanofibers. Moreover, the ferromagnetic moment is two
order of magnitude higher for nanofibers than that of nanoparticles, In
hexagonal phase, frustration of triangular lattice, works against the long
range ordering while magnetic anisotropy works in favor of the long range
ordering, which contributes towards the enhanced and anomalous magnetic
behavior in case of fibers. X -ray absorption near edge spectroscopy (XANES) at
the Fe K-edge has been used to probe the symmetry driven dynamics of Fe 3d- 4p
orbitals. It established that due to noncentrocymmetry of the Fe atom, the
nanofibers have decreased 3d-4p orbital mixing and reduced crystal field
splitting energy, which are also contributing factor for the enhanced magnetic
behaviour.
