Encapsulation of magnetic oxides inside carbon nanotubes

Abstract

Transition Metal Oxides TMOs are well known to host a diverse range of exotic electronic and magnetic ground states Carbon Nanotubes CNT on the other hand possess exceptional electrical thermal and mechanical properties This thesis presents a novel approach of encapsulating and preserving functional TMOs inside CNT thereby bringing into fore new possibilities in the arenas of nanoscience and nanotechnology and providing an opportunity for direct patterning of nano electronic devices With special focus on TMOs relevant to antiferromagnet AFM spintronics we have explored the fundamental as well as application based aspects of TMOs encapsulated inside CNT The transition metals and oxides when confined and protected within CNT can provide huge tunability in their functional properties as well as give rise to new emergent phenomena at the interface In this context we find that although FeatCNT have been extensively investigated encapsulation of other transition metals like Ni or Co and their respective oxides is rarely explored Even though magnetic oxides exhibit a remarkably wide range of properties oxide based electronics applications are still scarce In the first part of the thesis we demonstrate the use of a single zone furnace with a modified synthesis chamber design to obtain metal Fe Ni as well as their respective oxides filled carbon nanotubes with high filling efficiency and controlled morphology We employ pyrolysis of metallocene a technique which is well known to successfully yield Fe filled CNT but does not result in well formed Ni or Co filled CNT This is achieved by innovative use of a green compound camphor as a co precursor with metallocene Here the key result is an order of magnitude enhancement in the filling efficiency and controlled morphology in case of NiatCNT For AFM spintronics our attention has been on the encapsulation of a multi functional oxide 945 Fe2O3 hematite inside CNT Bulk 945 Fe2O3 is a well knownDzyaloshinskii Moriya Interaction driven canted AFM newline newline