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Insulator-to-metal transition in vanadium supersaturated silicon: variable-range hopping and Kondo effect signatures



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García Hemme, Eric and Montero Álvarez, Daniel and García Hernansanz, Rodrigo and Olea Ariza, Javier and Mártil de la Plaza, Ignacio and González Díaz, Germán (2016) Insulator-to-metal transition in vanadium supersaturated silicon: variable-range hopping and Kondo effect signatures. Journal of physics D: applied physics, 49 (27). ISSN 0022-3727

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Official URL: http://dx.doi.org/10.1088/0022-3727/49/27/275103


We report the observation of the insulator-to-metal transition in crystalline silicon samples supersaturated with vanadium. Ion implantation followed by pulsed laser melting and rapid resolidification produce high quality single-crystalline silicon samples with vanadium concentrations that exceed equilibrium values in more than 5 orders of magnitude. Temperature-dependent analysis of the conductivity and Hall mobility values for temperatures from 10K to 300K indicate that a transition from an insulating to a metallic phase is obtained at a vanadium concentration between 1.1 × 10^(20) and 1.3 × 10^(21) cm^(−3) . Samples in the insulating phase present a variable-range hopping transport mechanism with a Coulomb gap at the Fermi energy level. Electron wave function localization length increases from 61 to 82 nm as the vanadium concentration increases in the films, supporting the theory of impurity band merging from delocalization of levels states. On the metallic phase, electronic transport present a dispersion mechanism related with the Kondo effect, suggesting the presence of local magnetic moments in the vanadium supersaturated silicon material.

Item Type:Article
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© 2016 IOP Publishing Ltd. Authors would like to acknowledge the CAI de Técnicas Físicas of the Universidad Complutense de Madrid for the ion implantation procees and metallic evaporations. This work was partially supported by the Project MADRID-PV (Grant No. 2013/MAE-2780) funded by the Comunidad de Madrid, by the Spanish MINECO (Economic and Competitiviness Ministery) under grant TEC 2013-41730-R and by the Universidad Complutense de Madrid (Programa de Financiación de Grupos de Investigación UCM-Banco Santander) under grant 910173-2014. D Montero acknowledge the Spanish MINECO (Economic and Competitiviness Ministery) for financial support under contract BES-2014-067585.

Uncontrolled Keywords:Insulator-to-metal transition; Ion implantation; Kondo effect; Variable range; Hopping; Pulsed laser annealing.
Subjects:Sciences > Physics > Electricity
Sciences > Physics > Electronics
ID Code:39942
Deposited On:07 Nov 2016 14:43
Last Modified:10 Dec 2018 14:57

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