skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on September 30, 2021

Title: Superconducting magnesium diboride films for levitation of laser targets

Abstract

Inertial confinement fusion targets would benefit from being levitated inside hohlraums to avoid capsule support-related implosion perturbations. Levitation inside a magnetic trap requires coating the capsule with a thin film that is superconducting at 20 K. Such non-epitaxial film growth on non-planar substrates is challenging. Here, we study Mg vapor annealing and solid-phase reactive inter-diffusion methods to form superconducting magnesium diboride (MgB2) films on different planar and spherical carbon substrates, evaluating glassy carbon, polycrystalline diamond made by chemical vapor deposition, and carbon deposited by magnetron sputtering of graphite targets. Thin films of B and Mg are produced by magnetron sputtering onto stationary planar or rolling spherical substrates and annealed at either 600 or 850 °C in Mg vapor. The films are characterized by a combination of high-energy ion scattering, electron microscopy, and magnetometry. Results show that the critical superconducting temperature of resultant films depends on film microstructure and oxygen impurity content. The formation of MgB2 films is also strongly substrate dependent, even in this case of non-epitaxial growth. Important factors to consider are oxygen outgassing of the substrate during thermal processing, substrate surface roughness, and the matching of thermal expansion coefficients of different layers in the multilayer structure.

Authors:
ORCiD logo [1];  [1];  [2]; ORCiD logo [1];  [1];  [1];  [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  2. General Atomics, San Diego, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1647141
Alternate Identifier(s):
OSTI ID: 1776254
Report Number(s):
LLNL-JRNL-791922
Journal ID: ISSN 0040-6090; 991112
Grant/Contract Number:  
AC52-07NA27344; 17-ERD-040
Resource Type:
Accepted Manuscript
Journal Name:
Thin Solid Films
Additional Journal Information:
Journal Volume: 710; Journal ID: ISSN 0040-6090
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; magnesium diboride; military science; superconductivity; planar substrates; spherical substrates; vapor annealing; solid-phase reactive inter-diffusion

Citation Formats

Bayu Aji, L. B., Baker, A. A., Bae, J. H., Beckham, J. L., Jacob, R. E., Shin, S. J., McCall, S. K., and Kucheyev, S. O. Superconducting magnesium diboride films for levitation of laser targets. United States: N. p., 2020. Web. https://doi.org/10.1016/j.tsf.2020.138260.
Bayu Aji, L. B., Baker, A. A., Bae, J. H., Beckham, J. L., Jacob, R. E., Shin, S. J., McCall, S. K., & Kucheyev, S. O. Superconducting magnesium diboride films for levitation of laser targets. United States. https://doi.org/10.1016/j.tsf.2020.138260
Bayu Aji, L. B., Baker, A. A., Bae, J. H., Beckham, J. L., Jacob, R. E., Shin, S. J., McCall, S. K., and Kucheyev, S. O. Wed . "Superconducting magnesium diboride films for levitation of laser targets". United States. https://doi.org/10.1016/j.tsf.2020.138260.
@article{osti_1647141,
title = {Superconducting magnesium diboride films for levitation of laser targets},
author = {Bayu Aji, L. B. and Baker, A. A. and Bae, J. H. and Beckham, J. L. and Jacob, R. E. and Shin, S. J. and McCall, S. K. and Kucheyev, S. O.},
abstractNote = {Inertial confinement fusion targets would benefit from being levitated inside hohlraums to avoid capsule support-related implosion perturbations. Levitation inside a magnetic trap requires coating the capsule with a thin film that is superconducting at 20 K. Such non-epitaxial film growth on non-planar substrates is challenging. Here, we study Mg vapor annealing and solid-phase reactive inter-diffusion methods to form superconducting magnesium diboride (MgB2) films on different planar and spherical carbon substrates, evaluating glassy carbon, polycrystalline diamond made by chemical vapor deposition, and carbon deposited by magnetron sputtering of graphite targets. Thin films of B and Mg are produced by magnetron sputtering onto stationary planar or rolling spherical substrates and annealed at either 600 or 850 °C in Mg vapor. The films are characterized by a combination of high-energy ion scattering, electron microscopy, and magnetometry. Results show that the critical superconducting temperature of resultant films depends on film microstructure and oxygen impurity content. The formation of MgB2 films is also strongly substrate dependent, even in this case of non-epitaxial growth. Important factors to consider are oxygen outgassing of the substrate during thermal processing, substrate surface roughness, and the matching of thermal expansion coefficients of different layers in the multilayer structure.},
doi = {10.1016/j.tsf.2020.138260},
journal = {Thin Solid Films},
number = ,
volume = 710,
place = {United States},
year = {2020},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 30, 2021
Publisher's Version of Record

Save / Share: