Corroboration and efficacy of Magneto-Fluorescent (NiZnFe/CdS) Nanostructures Prepared using Differently Processed Core

Dipti Rawat,P B Barman,Ragini Raj Singh

doi:10.1038/s41598-019-51631-w

Dipti Rawat, P B Barman + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-51631-w

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Journal: Scientific Reports	Publication Date: Oct 22, 2019
Citations: 10	License type: open-access

Affiliation: Jaypee University of Information Technology

Abstract

The selected and controlled preparation of core@shell nanostructures, which unite the multiple functions of ferromagnetic Ni-Zn ferrite core and CdS shell in a single material with tuneable fluorescence and magnetic properties, have been proposed by the seed mediated aqueous growth process. The shell particle thickness and core of nanostructures were precisely tuned. Current work exhibits the comparative study of core@shell multifunctional nanostructures where core being annealed at two different temperatures. The core@shell nanostructure formation was confirmed by complementary structural, elemental, optical, magnetic and IR measurements. Optical and magnetic characterizations were performed to study elaborative effects of different structural combinations of core@shell nanostructures to achieve best configuration with high-luminescence and magnetic outcomes. The interface of magnetic/nonmagnetic NiZnFe2O4/CdS nanostructures was inspected. Unexpectedly, in some of the core@shell nanostructures presence of substantial exchange-bias was observed in spite of the non-magnetic nature of CdS QDs which is clearly an “optically-active” and “magnetically-inactive” material. Presence of “exchange-bias” was confirmed by the change in “magnetic-anisotropy” as well as shift in susceptibility derivative. Finally, successful formulation of stable and efficient core@shell nanostructures achieved, which shows no exchange-bias and shift. Current findings suggest that these magneto-fluorescent nanostructures can be used in spintronics; and drug delivery-diagnosis-imaging applications in nanomedicine field.

Highlights

Magnetic properties of the core and the interface in core@shell nanostructure have been studied using vibrating sample magnetometry measurements (VSM) at room temperature
NiZnFe2O4 annealed at 900 °C (Fig. 1(a)) and 1100 °C (Fig. 1(b)) have been indexed as (022), (113), (222), (004), (333), and (044) hkl planes indicating the formation of “single-phase spinel cubic structure” of nickel zinc ferrite (JCPDS No 52-0277)
On increasing the annealing temperature of NiZnFe2O4 from 900 °C to 1100 °C the crystallite size was found to be decreased from 29.96 nm to 23.75 nm as calculated using Scherrer’s formula. This decrease in crystallite size with increase in annealing temperature is due to increased micro strain[12]

Summary

Introduction

Magnetic properties of the core and the interface in core@shell nanostructure have been studied using vibrating sample magnetometry measurements (VSM) at room temperature. UV-visible spectrum for NiZnFe2O4, CdS QDs and their core@shell nanostructures have been recorded in order to study the optical behaviour of prepared structures (Fig. 2(a–d)) with different loadings of NiZnFe2O4.

Results

Conclusion