1. Temperature effect on the synthesis of 𝑭𝒆 𝟑 𝑶 𝟒 nano particles
Prasenjit Roy
EPR Spectroscopy Section, National Physical Laboratory, New Delhi-110012
𝐹𝑒3 𝑂4 Nano-particles were synthesized at different temperature from 30° to 60° C. Chemical co precipitation method was used in this respect. So particles
with different size were produced. Later on their structural properties were studied by X-ray diffraction method
Introduction ::
Magnetic fluid or Ferrofluids is a liquid dispersion of magnetic nanoparticles has a potential number of applications in different fields as magnetism, optics, rheology, biophysics, and biomedical. A magnetic
particle with a single magnetic domain is coated or stabilized by surfactant molecules to prevent them from aggregation. Out of the wide variety of Ferrofluids, 𝐹𝑒3 𝑂4 is the most widely used fluid and is the
base of all other application with suitable doping.
In the current work, 𝐹𝑒3 𝑂4 based Ferrofluids was synthesized at different temperature . And the change in their structural properties were studied. For my present work kerosene based oleic acid coated fluid
were synthesized . I have also synthesized water based double coated 𝐹𝑒3 𝑂4 Ferrofluid.
Core Shell Structure ::
The nano sized single domain particles are Preperation ::
coated with surfactant molecules. In case of
The process called chemical co-precipitation method. 4.33 g of 𝐹𝑒𝐶𝑙2 . 4𝐻2 𝑂 of 99% purity and 7.15 g of anhydrous 𝐹𝑒𝐶𝑙3 were mixed with water
polar ferrofluid, as water/alchohol based fluid,
to make 100 ml solution. Then both are magnetically stirred till the whole stuff dissolved. Then it is heated at 60 degree Celsius and oleic acid
there are two layer of surfactants whereas, in
were made. When the solution was made. It is kept inside a very precise temperature bath (accurate upto 0.01 K). When the solution reaches the
non-polar fluid based ferrofluid, only one layer of
temperature of the bath, Ammonium Hydroxide was added drop-wise to it till it reaches a pH level of 9. Finally the precipitation state stirred
surfactant is present giving it a stronger
again very well.
saturation magnetization.
𝐹𝑒𝐶𝑙3 + 𝐹𝑒𝐶𝑙2 + 𝑁𝐻4 𝑂𝐻 + 𝐻2 𝑂 → 𝐹𝑒3 𝑂4 + 𝑁𝐻4 𝐶𝑙
Finally this precipitation states is separated magnetically using a bar magnet. When the process is repeated 3-4 times, the precipitation is heated
on a hot plate and at last kerosene is added to it accordingly. Later on the colloidal solution is ultrasonicated for getting an equally dispersed
phase and finally centrifuged to separate out the larger particles.
Future Work::
The VSM study of the samples are to be
XRD Pattern ::
done along with the HRTEM of the
Non Polar The following XRD pattern was noted using Rigaku made X-ray samples so to find the actual size
Polar diffractometer. We can further calculate the strain from the distribution of particle inside the sample.
given data. Using the In the later stage, EPR study at different
Scherrer equation temperature of them will be studied in
Stability :: and the formula
ppf4 details.
Because there are two opposite forces acting one 4𝜖𝑠𝑖𝑛𝜃 =
Conclusion ::
against another, the fluid stability is depending 0.154
𝛽𝑐𝑜𝑠𝜃 − , The preparation stage of the
upon the thickness of the surfactant layer and the 𝐷
samples were kept same . But
diameter of the particle. we can find out
after the synthesis it was
the crystallite observed that the sample
Attraction
1. Dispersion Brownian size and the prepared at 50 °𝐶 was most
Forces ~ 𝑟 −6. Repulsion value of strain. stable . So we can optimized
Repulsion
~ KT the sample preparation .
2. Dipole
attraction ~ 𝑟 −3.
Prasenjit Roy is thankful to Dr. R. P. Pant for guiding him , Mr. Mahesh Chand for viscosity data and CSIR for providing fellowship.