Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solid-state Janus nanoprecipitation enables amorphous-like heat
  conduction in crystalline Mg3Sb2-based thermoelectric materials   Solid-state precipitation can be used to tailor materials properties, ranging
from ferromagnets and catalysts to mechanical strengthening and energy storage.
Thermoelectric properties can be modified by precipitation to enhance phonon
scattering while retaining charge-carrier transmission. Here, we uncover
unconventional dual Janus-type nanoprecipitates in Mg3Sb1.5Bi0.5 formed by
side-by-side Bi- and Ge-rich appendages, in contrast to separate
nanoprecipitate formation. These Janus nanoprecipitates result from local
co-melting of Bi and Ge during sintering, enabling an amorphous-like lattice
thermal conductivity. A precipitate size effect on phonon scattering is
observed due to the balance between alloy-disorder and nanoprecipitate
scattering. The thermoelectric figure-of-merit ZT reaches 0.6 near room
temperature and 1.6 at 773 K. The Janus nanoprecipitation can be introduced
into other materials and may act as a general property-tailoring mechanism.

8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess