トップページ » 過去に開催された講演会・セミナー » 過去に開催された講演会・セミナー(2011年度) » 第195回応用セラミックス研究所 講演会 (Prof. Chen, Pennsylvania Univ.)

第195回応用セラミックス研究所 講演会 (Prof. Chen, Pennsylvania Univ.)

開催日時 2011/06/20 14:00-15:00
開催場所 R3棟 1F 会議室
主催応用セラミックス研究所
連絡先問合せ:若井史博 (内線:5361)

プログラム等

講師: Mr. I-Wei Chen

        Professor, University of Pennsylvania

テーマ: A size-dependent nanoscale metal-insulator transition in random materials

<<講演概要>>

Insulators and conductors with periodic structures can be readily distinguished, because they have different band structures, but the differences between insulators and conductors with random structures are more subtle. In 1958, Anderson provided a straightforward criterion for distinguishing between random insulators and conductors, based on the ‘diffusion’ distance Z for electrons at 0 K. Insulators have a finite Z, but conductors have an infinite Z. Surprisingly, there have been no attempts to engineer a metal–insulator transition by making the sample size less than or more than Z.  Here, we report such an engineered transition using six different thin-film systems: two are glasses that contain dispersed platinum atoms, and four are single crystals of perovskite that contain minor conducting components.

 

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