Authors: Pragnya P Mishra M Manivel Raja Rabi N Panda
Publish Date: 2016/02/02
Volume: 29, Issue: 5, Pages: 1347-1356
Abstract
Nanocrystalline εFe3N and γ′Ni x Fe4−xN 02 ≤ x ≤ 08 nitride materials are synthesized in pure phase via solgelmediated oxide precursors The materials are characterized using XRD SEM EDX and magnetic measurements εFe3N and γ′Ni x Fe4−x N 02 ≤ x ≤ 08 materials crystallize in hexagonal and cubic structures respectively The lattice parameters are estimated to be a = 4781236 Å and c = 4423231 Å for εFe3N and in the range of 3792210–379573 Å for various γ′Ni x Fe4 −xN 02 ≤ x ≤ 08 materials The values of the lattice parameters show increasing trend up to x = 06 showing a peak and thereafter decreases with the increase in Ni weight percent in γ′Ni x Fe4−xN 02 ≤ x ≤ 08 materials The average crystallite sizes are in the range of 31–54 nm and confirm the nanocrystalline nature of the materials The SEM particle sizes are in the range of 1537–25014 nm For pure εFe3N the values of saturation magnetization M s and coercivity H c are 12 emu/g and 225 Oe respectively With the progressive substitution of Ni atoms hexagonal εphase changes to cubic γ′phase at the same reaction temperature which is evident from the increase in M s and H c values ie in the range of 144–181 emu/g and 76–109 Oe respectively for γ′Ni x Fe4 −xN 02 ≤ x ≤ 08 compounds The values of the saturation magnetization for γ′Ni x Fe4 −xN 02 ≤ x ≤ 08 are found to increase with the increase in Ni content in the materials up to the value of x = 06 and decrease thereafter These results have been interpreted in terms of size and shape effects in nanomaterials including lattice strain and surface effects
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