Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structure and magnetic properties of Heusler alloy Fe2NiZ (Z=Al, Ga, Si
  and Ge)   The Heusler alloys Fe2NiZ (Z=Al, Ga, Si and Ge) have been synthesized and
investigated focusing on the phase stability and the magnetic properties. The
experimental and theoretical results reveal the covalent bonding originated
from p-d hybridization takes an important role in these alloys, which dominates
the stability of ordered structure but leads to the decline of the band
splitting. The electronic structure shows the IV group main group element (Si
and Ge) provides stronger covalent effect than that of the III group element
(Al and Ga). It has been found that the variations of the physical parameters,
lattice constants, critical ordering temperature, magnetic moments and Curie
temperature, precisely follow these covalent characters.

31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg