Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Antisite pairs suppress the thermal conductivity of BAs   BAs was predicted to have an unusually high thermal conductivity at room
temperature of 2000$\,$Wm$^{-1}$$\,$K$^{-1}$, comparable to that of diamond.
However, the experimentally measured thermal conductivity of BAs single
crystals is an order of magnitude lower. To identify the origin of this large
inconsistency, we investigated the lattice structure and potential defects in
BAs single crystals at atomic scale using aberration-corrected scanning
transmission electron microscopy (STEM). Rather than finding a large
concentration As vacancies ($V_\mathrm{As}$), as widely thought to dominate the
thermal resistance in BAs crystals, our STEM results showed enhanced intensity
of some B columns and reduced intensity of some As columns, suggesting the
presence of antisite defects with As$_\mathrm{B}$ (As-atom on B site) and
B$_\mathrm{As}$ (B-atom on As site) with significant concentrations. Further
calculations show that the antisite pair with As$_\mathrm{B}$ next to
B$_\mathrm{As}$ is preferred energetically among the different types of point
defects investigated, and confirm that such defects lower the thermal
conductivity for BAs. Using a concentration of
6.6$\pm$3$\times$10$^{20}$$\,$cm$^{-3}$ for the antisite pairs estimated from
STEM images, thermal conductivity is estimated to be
65-100$\,$Wm$^{-1}$$\,$K$^{-1}$, in reasonable agreement with our measured
value. Our study suggests that As$_\mathrm{B}$-B$_\mathrm{As}$ antisite pairs
are the primary lattice defects suppressing thermal conductivity of BAs.
Possible approaches are proposed for growth of high quality crystals or films
with high thermal conductivity.

25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex