Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Progress in wire fabrication of iron-based superconductors   Iron-based superconductors, with Tc values up to 55 K, are of great interest
for applications, due to their lower anisotropies and ultrahigh upper critical
fields. In the past 4 years, great progress has been made in the fabrication of
iron-based superconducting wires and tapes using the powder-in-tube (PIT)
processing method, including main three types of 122, 11, and 1111 iron-based
parent compounds. In this article, an overview of the current state of
development of iron-based superconducting wires and tapes is presented. We
focus on the fabrication techniques used for 122 pnictide wires and tapes, with
an emphasis on their meeting the critical current requirements for making
high-performance conductors, such as a combination of using Ag sheath, addition
element and optimized heat treatment to realize high Jc, ex situ process
employed to reduce non-superconducting phases and to obtain a high relative
density, and a texture control to improve grain connectivity. Of particular
interest is that so far transport Jc values above 10^4 A/cm^2 at 4.2 K and 10 T
are obtained in 122 type tapes, suggesting that they are prospective candidates
for high-field applications. Finally, a perspective and future development of
PIT pnictide wires are also given.

1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci