title: NMR probe of metallic states in nanoscale topological insulators.
abstract: A 125Te NMR study of bismuth telluride nanoparticles as a function of particle size revealed that the spin-lattice relaxation is enhanced below 33 nm, accompanied by a transition of NMR spectra from the single to the 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 140-420 K, micrometer particles do so only below 200 K. The results reveal increased metallicity of these nanoscale topological insulators in the limit of higher surface-to-volume ratios.
authors: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors: Dimitrios
authors: D
authors: Koumoulis
authors: Thomas C
authors: TC
authors: Chasapis
authors: Robert E
authors: RE
authors: Taylor
authors: Michael P
authors: MP
authors: Lake
authors: Danny
authors: D
authors: King
authors: Nanette N
authors: NN
authors: Jarenwattananon
authors: Gregory A
authors: GA
authors: Fiete
authors: Mercouri G
authors: MG
authors: Kanatzidis
authors: Louis-S
authors: LS
authors: Bouchard