Colossal magnetoresistance in amino-functionalized graphene quantum dots at room temperature: manifestation of weak anti-localization and doorway to spintronics
| Autor: | Rajarshi Roy, Nilesh Mazumder, Gundam Sandeep Kumar, Nirmalya Sankar Das, Kalyan Kumar Chattopadhyay, Dipayan Sen, S. Sinthika, Ranjit Thapa |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Colossal magnetoresistance Condensed matter physics Spintronics Graphene Scattering 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Graphene quantum dot law.invention Magnetic field law Quantum dot 0103 physical sciences General Materials Science 010306 general physics 0210 nano-technology Ground state |
| Zdroj: | Nanoscale. 8:8245-8254 |
| ISSN: | 2040-3372 2040-3364 |
| DOI: | 10.1039/c5nr09292b |
| Popis: | In this work, we have demonstrated the signatures of localized surface distortions and disorders in functionalized graphene quantum dots (fGQD) and consequences in magneto-transport under weak field regime (∼1 Tesla) at room temperature. Observed positive colossal magnetoresistance (MR) and its suppression is primarily explained by weak anti-localization phenomenon where competitive valley (inter and intra) dependent scattering takes place at room temperature under low magnetic field; analogous to low mobility disordered graphene samples. Furthermore, using ab-initio analysis we show that sub-lattice sensitive spin-polarized ground state exists in the GQD as a result of pz orbital asymmetry in GQD carbon atoms with amino functional groups. This spin polarized ground state is believed to help the weak anti-localization dependent magneto transport by generating more disorder and strain in a GQD lattice under applied magnetic field and lays the premise for future graphene quantum dot based spintronic applications. |
| Databáze: | OpenAIRE |
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