Ananya Banerjee; A. Sarkar
Abstract
The objective of this paper is to investigate the magnetic nature of Dilute Magnetic Dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano sized Gadolinium Nickel Sulfide complex, Cobalt Sulfide, Nickel Sulfide and Titanium Sulfide as a DMD system. ...
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The objective of this paper is to investigate the magnetic nature of Dilute Magnetic Dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano sized Gadolinium Nickel Sulfide complex, Cobalt Sulfide, Nickel Sulfide and Titanium Sulfide as a DMD system. The observed experimental field variation of the effective magnetic permeability is the analyzed results of optical experiment. The experiment records the variation of Brewster angle of incident polarized LASER beam from the surface of developed DMD specimen with applied out of plane external magnetic field. The relative permittivity and relative magnetic permeability were estimated by following the electromagnetic theory. The overall results obtained are found to be holding a good agreement between theory and experiment.
S. Pal; A. Sarkar; D. Sanyal; T. Rakshit; D. Kanjilal; P. Kumar; S. K. Ray; D. Jana
Abstract
1.2 MeV Argon (Ar) ion irradiation turns white coloured ZnO to yellowish (fluence 1 × 10 14 ions/cm 2 ) and then reddish brown (1 × 10 14 ions/cm 2 ). At the same time the material becomes much more conducting and purely blue luminescent for the highest fluence of irradiation. To get ...
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1.2 MeV Argon (Ar) ion irradiation turns white coloured ZnO to yellowish (fluence 1 × 10 14 ions/cm 2 ) and then reddish brown (1 × 10 14 ions/cm 2 ). At the same time the material becomes much more conducting and purely blue luminescent for the highest fluence of irradiation. To get insight on the defects in the irradiated samples Ultraviolet-visible (UV-vis) absorption, Raman, and photoluminescence (PL) spectroscopy and Glancing Angle X-Ray Diffraction (GAXRD) measurements have been carried out. Enhancement of overall disorder in the irradiated samples is reflected from the GAXRD peak broadening. UV-vis absorption spectra of the samples shows new absorption bands due to irradiation. Complete absorption in the blue region of the spectrum and partial absorption in the green and red region changes the sample colour from white to reddish brown. The Raman peak representing wurtzite structure of the ZnO material (~ 437 cm -1 ) has decreased monotonically with the increase of irradiation fluence. At the same time, evolution of the 575 cm -1 Raman mode in the irradiated samples shows the increase of oxygen deficient disorder like zinc interstitials (IZn) and/or oxygen vacancies (VO) in ZnO. PL spectrum of the yellow coloured sample shows large reduction of overall luminescence compared to the unirradiated one. Further increase of fluence causes an increase of luminescence in the blue region of the spectrum. The blue-violet emission can be associated with the interstitial Zn (IZn) related optical transition. The results altogether indicates IZn type defects in the highest fluence irradiated sample. Large changes in the electrical resistance and luminescent features of ZnO using Ar ion beam provides a purposeful way to tune the optoelectronic properties of ZnO based devices.
