NMR Probe of Metallic States in Nanoscale Topological Insulators

Autor:	Koumoulis, Dimitrios, Chasapis, Thomas C., Taylor, Robert E., Lake, Michael P., King, Danny, Jarenwattananon, Nanette N., Fiete, Gregory A., Kanatzidis, Mercouri G., Bouchard, Louis-S.
Rok vydání:	2013
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter - Materials Science
Zdroj:	Phys. Rev. Lett. 110, 026602 (2013)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevLett.110.026602
Popis:	A 125Te NMR study of bismuth telluride nanoparticles as function of particle size revealed that the spin-lattice relaxation is enhanced below 33 nm, accompanied by a transition of NMR spectra from single to bimodal regime. The satellite peak features a negative Knight shift and higher relaxivity, consistent with core polarization from p-band carriers. Whereas nanocrystals follow a Korringa law in the range 140-420K, micrometer particles do so only below 200K. The results reveal increased metallicity of these nanoscale topological insulators in the limit of higher surface-to-volume ratios. Comment: 17 pages, 4 figures, 1 table
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1301.2819 Zobrazit plný text záznamu View this record from Arxiv