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Present work reports a comparative study of spectroscopic and magneto-optic properties of FeO based ferrofluids prepared with two different carrier fluid namely milli-Q-water and kerosene. The ferrofluids are labelled as FFW and FFK respectively. Both ferrofluids are subjected to γ-irradiation of dose: 2,635 Gy. Transmission electron microscopy and dynamic light scattering studies reveal that γ-photon interaction could lead to substantial growth of the dispersed nanoparticles of ferrofluids. In case of FFW, particle sizes are ~9 nm (pristine) and ~48 nm (irradiated) whereas, in FFK unirradiated particles of size ~9 nm show growth to ~18 nm after the irradiation. The role of different physical parameters (viz. viscosity, density) of carrier fluid on the growth process is considered in this regard. Viscosity of the carrier fluid is found noteworthy in the measurement of Faraday rotation response of the ferrofluids. In addition to low viscosity of water, irradiation induced particle growth as well as improved size distribution with larger particles leads to a comparatively larger enhancement of Faraday rotation of FFW than that of FFK. Consequently, as a result of γ-irradiation, Verdet constant is modified by ~70 % in the former case and by ~60 % in the latter case. [ABSTRACT FROM AUTHOR]

Hydroxyl free zinc oxide nanorods have been synthesized by a catalyst free surfactant based one-step solid state reaction process. The powder X-ray diffraction studies reveal well defined wurtzite peaks due to crystalline ZnO, while optical absorption spectra represent prominent exciton absorption and remarkable blueshift in the onset of absorption. As predicted by transmission electron microscopy, the ZnO nanorods are ∼100 nm long and of ∼20 nm dia. Further, luminescence aspects of such nanorods are studied for possible deployment in optoelectronics devices. [ABSTRACT FROM AUTHOR]