%0 Journal Article
%T NMR Probe of Metallic States in Nanoscale Topological Insulators
%A Dimitrios Koumoulis
%A Thomas C. Chasapis
%A Robert E. Taylor
%A Michael P. Lake
%A Danny King
%A Nanette N. Jarenwattananon
%A Gregory A. Fiete
%A Mercouri G. Kanatzidis
%A Louis-S. Bouchard
%J Physics
%D 2013
%I arXiv
%R 10.1103/PhysRevLett.110.026602
%X 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.
%U http://arxiv.org/abs/1301.2819v1