TY - JOUR
T1 - NMR probe of metallic states in nanoscale topological insulators
AU - Koumoulis, Dimitrios
AU - Chasapis, Thomas C.
AU - Taylor, Robert E.
AU - Lake, Michael P.
AU - King, Danny
AU - Jarenwattananon, Nanette N.
AU - Fiete, Gregory A.
AU - Kanatzidis, Mercouri G.
AU - Bouchard, Louis S.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/1/9
Y1 - 2013/1/9
N2 - A Te125 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.
AB - A Te125 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.
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U2 - 10.1103/PhysRevLett.110.026602
DO - 10.1103/PhysRevLett.110.026602
M3 - Article
AN - SCOPUS:84872153846
VL - 110
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 2
M1 - 026602
ER -