| Synthesis and Characterization of Sodium Potassium
Niobate and Cobalt Ferrite Multiferroic Composites |
Kommuri Kirana,* Vagmare Gangadhar and Guduru Prasad
Pages : 100-105
DOI : 10.1080/0371750X.2018.1465359 |
| Abstract |
| The composite materials with composition xNa0.5K0.5NbO3-(1–x)CoFe2O4 with
x = 0.2, 0.4, 0.5, 0.6, 0.8, 0.9 and 1.0 are combination of ferroelectric Na0.5K0.5NbO3
(NKN) and ferrimagnetic CoFe2O4 (CFO) compounds. NKN is a combination of
ferroelectric KNbO3 and antiferroelectric NaNbO3, with morphotropic phase boundary
and exhibits two phase transitions around 220oC and 430oC. CFO is a ferrimagnetic
material with inverse spinel cubic structure. Therefore the triphasic composite is
expected to be a good magneto-electric material. NKN is synthesized by solid state
double sintering method. XRD studies confirm single phase formation and
orthorhombic structure. The composites are fabricated by taking stoichiometric
amounts of NKN and CFO powders, ground for 6 h, made into green square pellets
and kept for sintering at 1000oC for 5 h. XRD studies reveal the presence of peaks
corresponding to both NKN and CFO. Density of the composites increased with
addition of CFO; SEM images indicate the change in shape and size of grains. EDS
studies confirm the presence of estimated atomic and weight percentages of all the
composites. FTIR studies reveal the presence of multiple peaks in the 1000-1600
cm–1 region due to Na-O, K-O vibrations and at ~450 and 584 cm–1 due to Fe-O and
Co-O bonds. Dielectric measurements show the variation of transition temperatures
with the change in composition. Impedance studies confirm the increasing
conducting behaviour of composites with increasing concentration of CFO.
[Keywords: Multiferroics, Composites, Ferroelectrics, Dielectric properties,
Impedance studies] |
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