Sonochemical synthesis, structural, electrical transport and magnetic properties of NiWO 4 nanoparticles
- PDF / 3,178,358 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 96 Downloads / 194 Views
Sonochemical synthesis, structural, electrical transport and magnetic properties of NiWO4 nanoparticles S. Shanmugapriya1 · V. D. Nithya1 · A. Rajalakshmi1 · K. S. Sivaranjani1 · P. Bharathi1 · S. Shalini1 · P. Rupa Kasturi1 · R. Kalai Selvan1 Received: 25 April 2020 / Accepted: 28 July 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The NiWO4 nanoparticles are synthesized by the facile sonochemical method and characterized using various analytical techniques. The thermal stability and the crystallization temperature of the as-prepared N iWO4 were revealed using thermogravimetric and differential thermal analysis (TG/DTA). Phase purity and crystallinity of wolframite type monoclinic structure of N iWO4 nanoparticles were corroborated using the X-ray diffraction (XRD) analysis. Fourier transform infrared spectroscopy (FTIR) employed to understand the bending and stretching vibrations of the M–O bonds and the surface functional groups present in N iWO4. The average particle size of 25 nm with nearly spherical morphology of the N iWO4 nanoparticles was inferred using both scanning electron microscopic (SEM) and transmission electron microscopic (TEM) techniques. A comparative impedance spectral analysis was carried out at both room (300 K) and high temperature (973 K) to analyze the temperature-dependent conductance behaviour of NiWO4 nanoparticles. The negative temperature coefficient of resistance (NTCR) behaviour of N iWO4 nanoparticles was revealed through the decreasing resistance with increasing temperature and obtained the d.c. conductivity of 7.493 × 10−8 S cm−1 at 973 K. The hopping conduction mechanism and thermally activated mobility of charge carriers were observed in the present study. Further, the dielectric study infers the contributions of grain boundaries and grains at low and high frequencies, respectively. Finally, the room temperature paramagnetic behaviour of the NiWO4 is corroborated through vibrating sample magnetometer (VSM) analysis.
1 Introduction The wolframite structured metal tungstates ( MWO4; M = Co, Ni, Mg, Mn, Cu, Zn, etc.) provides interesting, structural electrical and optical properties [1], where NiWO4 is found interesting due to its low bandgap value [2]. NiWO4 falls under the isomorphous series of metal tungstates, and it is an antiferromagnetic compound with a Neel temperature of 67 K [3]. It has a wolframite structure, which comes from the distorted hexagonal close packing of O atoms with Ni and W atoms, where each atom are occupying one-fourth of the octahedral interstices [3]. The monoclinic wolframite structured NiWO4 had attracted remarkable attention in various potential applications including photocatalyst [4], electrocatalyst [5], supercapacitor [6, 7], biosensor [8], gas sensors [9], water splitting [10], microwave device [11], * R. Kalai Selvan [email protected] 1
Department of Physics, Bharathiar University, Coimbatore, Tamil Nadu 641 046, India
photoanodes [12], nonlinear optical materials [13], antib
Data Loading...
