NMR Probe of Metallic States in Nanoscale Topological Insulators

Dimitrios Koumoulis; Thomas C. Chasapis; Robert E. Taylor; Michael P. Lake; Danny King; Nanette N. Jarenwattananon; Gregory A. Fiete; Mercouri G. Kanatzidis; Louis-S. Bouchard

doi:10.1103/PhysRevLett.110.026602

NMR Probe of Metallic States in Nanoscale Topological Insulators

Mesoscale and Nanoscale Physics 2013-01-15 v1 Materials Science

Authors: Dimitrios Koumoulis , Thomas C. Chasapis , Robert E. Taylor , Michael P. Lake , Danny King , Nanette N. Jarenwattananon , Gregory A. Fiete , Mercouri G. Kanatzidis , Louis-S. Bouchard

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Abstract

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.

Keywords

NMR topological insulators bismuth telluride nanoparticles spin-lattice relaxation Knight shift metallicity

Cite

@article{arxiv.1301.2819,
  title  = {NMR Probe of Metallic States in Nanoscale Topological Insulators},
  author = {Dimitrios Koumoulis and Thomas C. Chasapis and Robert E. Taylor and Michael P. Lake and Danny King and Nanette N. Jarenwattananon and Gregory A. Fiete and Mercouri G. Kanatzidis and Louis-S. Bouchard},
  journal= {arXiv preprint arXiv:1301.2819},
  year   = {2013}
}

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17 pages, 4 figures, 1 table

NMR Probe of Metallic States in Nanoscale Topological Insulators

Abstract

Keywords

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