Indian Science Technology and Engineering facilities Map
 
Supplier Map
Service Map

Publications

Publication Details

Applicant:
Indian Institute of Technology (IIT) Patna 
Author:
A Kumar, K Kumari, S J Ray, Ajay D Thakur 
Corresponding Authors:
A Kumar 
DOI #:
https://doi.org/10.1063/5.0009666 
Title:
Graphene mediated resistive switching and thermoelectric behavior in lanthanum cobaltate 
Journal:
Journal of Applied Physics 
Year:
2020 
Volume:
127 
Page:
235103 
Keywords:
Graphene, resistive switching 
Abstract:
Multifunctional materials are of utmost importance owing to the combination of several functionalities into a single device. We present the multifunctional properties, namely, thermoelectric (TE) for energy harvesting and resistive switching (RS) for memory storage in the LaCoO3 (LCO)–graphene nanocomposite system. The existence of individual phases of LCO and graphene is confirmed from x-ray diffraction and electron microscopy techniques. The x-ray photoelectron spectroscopy measurement reveals the formation of oxygen vacancies in the nanocomposite with the addition of graphene. The bipolar resistive switching behavior observed in a LCO–graphene nanocomposite is explained using space charge limited conduction mechanism and is found to evolve from a trap-limited to a trap-free region with an increase in the graphene volume fraction, which eventually ascribed to the ordering of oxygen vacancies in the nanocomposite system. The endurance plot of the nanocomposite shows a stable RS behavior for consecutive 1000 cycles. On the other hand, the creation of oxygen vacancies in the nanocomposite leads to change in the configurational entropy of charge states of cobalt, which tunes the Seebeck coefficient (α). The decrease in α leads to an increase in the hopping hole concentration (nh) estimated using the classical Heikes formula and is consistent with the increase in the electrical conductivity. The increase in oxygen vacancies leads to point-defect scattering, which further reduces the thermal conductivity of the nanocomposite. The optimized TE parameters show a figure-of-merit of 0:004 + 0:000 48 at 300 K. The simultaneous observation of RS and TE properties in LCO–graphene nanocomposite provides new directions for multifunctional materials. 
Entered by:
Physics Head on 2020-08-01 
 
THE VISION
THE MISSION
ABOUT I-STEM
It has always been the basic tenet of the Government of India, in generously funding R&D efforts at academic institutions over the years, that facilities established through such support be made available to those needing them and qualified to make use of them for their own research work
read more >>

However, this was never easy or straightforward for, among other reasons, there was no ready source of information of what facility was available and where. Thanks to the Web, it is much easier today to have a national and regional “inventory of resources”, so as to match users with the resources they need, and to do all this in an efficient and transparent manner.

This can lead to a leap in R&D productivity and greatly enhance the effectiveness of public investment. This is the motivation behind I-STEM.
read less <<
Visitor Hit Counter
Hosted at Indian Institute of Science
Copyright © 2024 I-STEM. All rights reserved.
Audited by: STQC Bengaluru.