Realization of high-temperature superconductivity in carbon-nanotubes and its low power applications
Abstract
Superconductivity (SC) is a hot topic in condensed matter physics and also key factor for applications to zero-emission energy system. In particular, SC in carbon nanotubes (CNTs) has been expected to have high transition temperature (Tc), because of its high phonon frequency due to the small mass, extremely high one-dimensional (1D) electronic density of state (EDOS) due to van Hove singularity, and strong electron-phonon coupling between a radial breathing phonon mode and hybrid orbital electrons. Previously, I tried to realize high-Tc SC in thin films consisting of randomly placed CNTs based on such advantages. Moreover, I applied ionic-gel (liquid) gating to the CNT thin films in order to cause extremely high EDOS on the surface and obtained Tc as high as 38K, however its reproducibility was too poor. Here, in the present work, I use novel solution (i.e., hexadecyltrimethylammonium bromide (CTAB)) to chemically modify CNT surface and create thin films consisting of highly oriented (aligned) CNTs with flat and homogeneous surface, which should resolve the problem of poor reproducibility and realize high-Tc SC. High reproducibility is obtained in partially oriented CNTs with the ionic-liquid gate by this approach, while the observed Tc is low (< 20K). On the other hand, possibly high-oriented MWNTs with CTAB solution confined into micro-trenches on substrate demonstrate high Tc (> 40K), while the reproducibility is poor. Further optimization based on this approach may realize higher Tc with high reproducibility.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 19, 2018
- Accession Number
- AD1054668
Entities
People
- Junji Haruyama
Organizations
- Aoyama Gakuin University