The effect of Ni/Fe ratio on the physical properties of NiFe2O4 nanocomposites
Abstract
Spinelferritesnanoparticleswerepreparedusinghydrothermaltechnique.TheatomicratioofNito Feinthesolutionisrangedfrom0to75%inordertoinvestigateitseffectonthestructural, morphologicalandmagneticpropertiesofthepreparedspinelphases.Thepowdercrystallographic structurewasstudiedbymeansofx-raydiffraction(XRD).Themorphologywasstudiedusing scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM)andhighresolution transmissionelectronmicroscopy(HRTEM)observations.Vibratingsamplemagnetometer(VSM) wasusedtocharacterizethemagneticpropertiesofpowders.TheXRDanalysisrevealsthatthe powderspreparedwithratiosNi/Feof25and50%arepurenickelferritephase.However,at75% ratiothepowderisamixtureofhematiteandmainlynickelhydroxide.Theobtainednickelferrites shownarrowdistributionofgrainsizewhichisreducedwithincreasingtheNi/Feratio;thisvariation isexplainedintermsofnucleationandgraingrowth.Nickelferritenanopowdersexhibita superparamagneticbehavior,duetotheirsmallsize,andhighmagnetizationsaturationof 29.88emug−1.Thereafter,thepreparedpowdersmayfoundbiomedicalapplicationssuchasdrug delivery.