Sensor Performance and Structural Characteristics of Cr_xFe_3-xO₄Ferrofluids

The CrxFe3-xO4 ferrofluids have been successfully synthesized using natural iron sand through co-precipitation method as a voltage sensor. The use of chromium dopants is intended to increase the ferrofluids response when used as a voltage sensor. A series of characterizations were carried out to support this justification, including structure, morphology, functional groups, optical properties, and sensor performance of the CrxFe3-xO4 ferrofluids. The increase in the Cr3+ molar fraction has an impact on decreasing in structural parameters of the CrxFe3-xO4 ferrofluids. Visually, the particles show an agglomeration phase by the presence of interparticle forces. The study of functional groups showed that the CrxFe3-xO4 ferrofluids had been successfully formed, marked by the appearance of all precursor functional groups. Analysis of optical properties based on absorption shows the phenomenon of intervalence charge transfer and causes a decrease in the value of the gap energy. Interestingly, the CrxFe3-xO4 ferrofluids sensor sensitivity shows a good and prospective response making them suitable for new sensor candidates in the future.