Ecofriendly synthesis, crystal chemistry, electrical, and low-temperature magnetic properties of nano-particles (Li-Cr) for drug delivery and MRI applications

Mixed Li(0.5-x/2)Fe(2.5-x/2)CrxO4 (X = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) nano-ferrite system was synthesized by using Citrate gel auto-combustion method. Structural parameters such as lattice constant, hopping length, and X-ray density were reported and discussed with composition. The surface morphology was presented and explained with TEM analysis and SAED patterns. XRD patterns show the prepared samples are single-phase cubic spinel structure and the average particle size lies between 17 to 27 nm. TEM analysis shows prepared sample are the crystallite formation in nano-size. DC electrical properties presented variation with temperature and composition were discussed and studied well behind the Curie temperature. Magnetic measurements are carryout with VSM (Vibrating Sample Magnetometer), Observations have shown that magnetic properties are strongly influenced due to the substitution of Cr3+ in Lithium ferrites. Two samples Li0.5Cr0.6Fe1.9O4 and Li0.5Cr1.0Fe1.5O4 were subjected to an applied field of 100 Oe between 5 and 375 K temperature for ZFC and FC (Zero Field Cooled and Field Cooled) measurements of magnetization which indicated blocking temperature at around 350 K for both samples beyond which they exhibited super-paramagnetic behavior.

Automated summary

In this study, a series of mixed Li-Fe-Cr oxide nano-ferrite systems were successfully synthesized using the citrate gel auto-combustion method. Structural parameters and surface morphology were characterized, showing that Cr3+ substitution significantly influenced the magnetic properties. The magnetic behavior of two samples exhibited super-paramagnetic behavior at high temperatures.