Srivastava, R. C.Dhyani, Reena2022-12-012022-12-012022-05https://krishikosh.egranth.ac.in/handle/1/5810190229Present work is an attempt to observe the properties of CoxCu1-xFe2O4 (x= 0.0, 0.5 & 1.0), polypyrrole (PPy), Co0.5Cu0.5Fe2O4/PPy nanocomposites and to study the effect of 120 MeV Ag ion beam irradiation on the properties of synthesized samples. The simple and cost effective methods were utilized for the synthesis of CoxCu1-xFe2O4 (x=0.0, 0.5 & 1.0), PPy and Co0.5Cu0.5Fe2O4/PPy nanocomposites (consisting 25, 50 & 75% of PPy). XRD, FTIR, Raman, UV-Visible, SEM, EDX, and VSM characterization techniques were used to determine the properties of the synthesized samples. Electrical properties were investigated by using dielectric and resistivity measurement. XRD pattern confirmed the successful formation of all synthesized samples. The overall magnetic and dielectric properties of Co0.5Cu0.5Fe2O4 (CCF) sample is superior to CuFe2O4 and CoFe2O4. For CoxCu1-xFe2O4 (x=0.0, 0.5 & 1.0), the P-E loop is almost a circle which shows the presence of weak ferroelectric behaviour. In CCF/PPy nanocomposites the magnetic parameters were found to reduce with increasing the wt % of PPy. The EPR line width gets narrower and resonance magnetic field is shifted towards the lower values as the wt % of PPy is increased. The improved thermal stability was observed for CCF/PPy nanocomposites in comparison to PPy. Further,120 MeV Ag ion beam at fluence of 1×1012 ionscm-2, 5×1012 ionscm-2, and 1×1013 ionscm-2 with a fixed current of 1pnA were used to irradiate the CCF, PPy and CCF/PPy nanocomposite (consists of 50 % PPy). From XRD analysis of irradiated samples, it was confirmed that neither crystal structure was disturbed nor any new phase formed upon SHI irradiation. After irradiation, the crystallinity of CCF and CCF/PPy nanocomposites was reduced while improved crystallinity was observed for PPy. FTIR and Raman spectra of irradiated CCF and CCF/PPy nanocomposites show a slight shift in band positions relative to their pristine samples. The sensitivity of various Raman modes is different at different fluence of SHI. A significant change was observed in FTIR and Raman spectra of irradiated PPy at the highest fluence of 1×1013 ionscm-2. It assured instability of PPy toward the high fluence of SHI. The saturation magnetization of CCF was reduced up to fluence of 5×1012 ionscm-2 and starts to increase at 1×1013 ionscm- 2. In irradiated CCF/PPy nanocomposites, the condition of magnetic saturation was not achieved, although a complete hysteresis loop was observed. In CCF/PPy nanocomposites, the narrowing effect of EPR line width indicates increased intraparticle superexchange interaction upon SHI irradiation. The overall outcomes suggest that microstructure plays dominating role in deciding the behaviour of target material towards the irradiation.EnglishThesis