Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sparking mashups to form multifunctional alloy nanoparticles   Synthesizing unconventional alloys remains challenging owing to seamless
interactions between kinetics and thermodynamics. High entropy alloys (HEAs),
for example, draw a fundamentally new concept to enable exploring unknown
regions in phase diagrams. The exploration, however, is hindered by traditional
metallurgies based on liquid-solid transformation. Vapor-solid transformation
that is permissible on pressure-temperature phase diagrams, offers the most
kinetically efficient pathway to form any desired alloy (e.g., HEA). Here, we
report that a technique called "sparking mashups", which involves a rapidly
quenched vapor source and induces unrestricted mixing for alloying 55 distinct
types of ultrasmall nanoparticles (NPs) with controllable compositions. Unlike
the precursor feed in wet chemistry, a microseconds-long oscillatory spark
controls the vapour composition, which is eventually retained in the alloy NPs.
The resulting NPs range from binary to HEAs with marked thermal stability at
room temperature. We show that a nanosize-effect ensures such thermal stability
and mimics the role of mixing entropy in HEAs. This discovery contradicts the
traditional "smaller is less stable" view while enabling the elemental
combinations that have never been alloyed to date. We even break the
miscibility limits by mixing bulk-immiscible systems in alloy NPs. As powerful
examples, we demonstrate the alloy NPs as both high-performance fuel-cell
catalysts and building blocks for three-dimensional (3D) nanoprinting to
construct HEA nanostructure arrays of various architectures and compositions.
Our results form the basis of new rules for guiding HEA-NP synthesis and
advancing catalysis and 3D printing to new frontiers.

12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
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The categories of this paper are: stat
29
The categories of this paper are: funct-an
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg