Title: The growth and nanothermite reaction of 2Al/3NiO multilayer thin films

Abstract

Nanothermite NiO–Al is a promising material system for low gas emission heat sources; still, its reactive properties are highly dependent on material processing conditions. In the current study, sputter deposition is used to fabricate highly controlled nanolaminates comprised of alternating NiO and Al layers. Films having an overall stoichiometry of 2Al to 3NiO were produced with different bilayer thicknesses to investigate how ignition and self-sustained, high temperature reactions vary with changes to nanometer-scale periodicity and preheat conditions. Ignition studies were carried out with both hot plate and laser irradiation and compared to slow heating studies in hot-stage x-ray diffraction. Ignition behavior has bilayer thickness and heating rate dependencies. The 2Al/3NiO with λ ≤ 300 nm ignited via solid/solid diffusion mixing (activation energy, E_a = 49 ± 3 kJ/mole). Multilayers having λ ≥ 500 nm required a more favorable mixing kinetics of solid/liquid dissolution into molten Al (E_a = 30 ± 4 kJ/mole). This solid/liquid dissolution E_a is a factor of 5 lower than that of the previously reported powder compacts due to the elimination of a passivating Al oxide layer present on the powder. The reactant mixing mechanism between 300 and 500 nm bilayer thicknesses was dependent on the ignitionmore » source's heating rate. The self-propagating reaction velocities of 2Al/3NiO multilayers varied from 0.4 to 2.5 m/s. Pre-heating nanolaminates to temperatures below the onset reaction temperatures associated with forming intermediate nickel aluminides at multilayer interfaces led to increased propagation velocities, whereas pre-heating samples above the onset temperatures inhibited subsequent attempts at laser ignition.« less

Authors:

Abere, Michael J.  ^[1];

• Search DOE PAGES for author "Abere, Michael J."
• Search DOE PAGES for ORCID "0000-0002-3901-6478"

Beason, Matthew T.  ^[2];

• Search DOE PAGES for author "Beason, Matthew T."
• Search DOE PAGES for ORCID "0000-0002-2056-7456"

Reeves, Robert V. ^[3]; Rodriguez, Mark A. ^[1]; Kotula, Paul G.  ^[1];

• Search DOE PAGES for author "Kotula, Paul G."
• Search DOE PAGES for ORCID "0000-0002-7521-2759"

Sobczak, Catherine E.  ^[1];

• Search DOE PAGES for author "Sobczak, Catherine E."
• Search DOE PAGES for ORCID "0000-0002-2857-4597"

Son, Steven F.  ^[2];

• Search DOE PAGES for author "Son, Steven F."
• Search DOE PAGES for ORCID "0000-0001-7498-2922"

Yarrington, Cole D. ^[1]; Adams, David P. ^[1]

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+ Show Author Affiliations

1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. Purdue Univ., West Lafayette, IN (United States)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:

Wed Jul 20 00:00:00 EDT 2022

Research Org.:

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:

USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP)

OSTI Identifier:

1882614

Alternate Identifier(s):

OSTI ID: 1876915

Report Number(s):

SAND2022-10187J
Journal ID: ISSN 0021-8979; 708700; TRN: US2308138

Grant/Contract Number:  

NA0003525; NA0002377

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Volume: 132; Journal Issue: 3; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; laser beam effects; thin films; diffusion barriers; nanomaterials; transmission electron microscopy; x-ray diffraction; sputter deposition