Kumar, Upendra and Ansaree, Md Jawed and Verma, Atul Kumar and Upadhyay, Shail and Gupta, Govind (2017) Oxygen vacancy induced electrical conduction and room temperature ferromagnetism in system BaSn1-xNixO3 (0 <= x <= 0.20). Materials Research Express, 4 (116304). 116304-1-116304-16. ISSN 2053-1591

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Abstract

Powder and ceramics of few compositions of BaSn1-xNixO3 (with x = 0, 0.05, 0.10 and 0.20) have been prepared bysolid-state reaction route. Synthesized samples have been characterized using XRD, FTIR, SEM and XPS techniques. XPS studies have shown that all samples contain a significant number of oxygen vacancies (V-O), Ba is present in the Ba2+ state, Sn is present in both Sn2+ and Sn4+ states and Ni exists mainly in the Ni2+ state. The AC conductivity spectra of all compositions followed universal Johnscher's power law and the time-temperature superposition principle (TTSP). Above 300 degrees C conduction in these samples is governed by long-range diffusion of doubly ionized oxygen vacancies (V-<(O)double over dot>). M-H loop at room temperature shows that undoped BaSnO3 is ferromagnetic with saturation magnetization (M-s) similar to 5.46 x 10(-3) emu g(-1) and coercive field (H-c) similar to 540 Oe, due to spins of electrons trapped in oxygen vacancies (F-center) and direct interaction between F-centers. Ni-doped samples exhibit both ferromagnetic and paramagnetic behavior and paramagnetic contribution increases with doping concentration. The room temperature magnetic parameters have been extracted by fitting the experimental data to the bound magnetic polaron (BMP) model. The saturation magnetization increases whereas coercive field decrease with increasing concentration of dopant (Ni).

Item Type:	Article
Additional Information:	Copyright for this article belongs to M\S IOP Publishing.
Subjects:	Materials Science
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	07 Dec 2018 07:41
Last Modified:	07 Dec 2018 07:41
URI:	http://npl.csircentral.net/id/eprint/2816

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