Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/30738
Title: Electrical, dielectric and magnetocaloric properties of selected A- and B-site substituted manganites
Authors: SUJIT KUMAR BARIK
Keywords: Manganite, Colossal Magnetoresistance, Phase separation, Magnetoimpedance, Magnetocaloric effect, Dielectric properties
Issue Date: 14-Jun-2011
Source: SUJIT KUMAR BARIK (2011-06-14). Electrical, dielectric and magnetocaloric properties of selected A- and B-site substituted manganites. ScholarBank@NUS Repository.
Abstract: In my thesis work, I have investigated electrical, magnetotransport (dc and ac), dielectric and magnetocaloric properties in selected A- and B-site substituted manganites having the general formula ABO3, where A=RE1-xAEx (RE=La3+, Pr3+, Nd3+and AE=Sr2+, Ca2+) and B=Mn. The investigated systems are: La0.7-xBixSr0.3MnO3 (A-site doped), La0.7Sr0.3Mn1-xFexO3 (B-site doped) and La0.5Ca0.5Mn1-xNixO3 (B-site doped). We show that both A-site and B-site doping in La0.7Sr0.3MnO3 converts the ferromagnetic metal into antiferromagnetic insulator although the mechanisms by which it takes place are different. Investigation of high frequency electrical properties in these compounds revealed unusually large ac magnetoresistance in metallic compositions, whereas the insulating compositions showed dielectric properties. Influence of A- and B-site doping on magnetic entropy change has been studied. Magnetic Phase diagrams have been obtained. In contrast to the above two series of compounds, Ni doping in La0.5Ca0.5Mn1-xNixO3 converts the charge ordered insulator into a ferromagnetic metal. The ac magnetotransport properties of this compound are shown to be strikingly different from the above two series of compounds.
URI: http://scholarbank.nus.edu.sg/handle/10635/30738
Appears in Collections:Ph.D Theses (Open)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
BarikSujitKumar.pdf13.91 MBAdobe PDF

OPEN

NoneView/Download

Page view(s)

308
checked on Dec 11, 2017

Download(s)

519
checked on Dec 11, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.