First-Principles Study of Electronic, Magnetic, and Optical properties of the Intermetallic Compounds Ni 3 Mn Doped with Al

Abstract

In this paper, we have calculated the electronic, magnetic, and optical properties of Ni3Mn1 − x
Alx
(x = 0, 0.25, 0.50, 0.75), using a spin-polarized scalar relativistic linear muffin-tin orbital (SPR-LMTO) method within density functional theory (DFT). The spin–orbit coupling was included as a perturbation in the self-consistent iterations. In our calculations for densities of states, we have used in all alloys the energy (E) range from −10 to + 10 eV. And for the optical spectra in all alloys, we have used the same energy range from 0.083 to 5.640 eV. In this work, we have discussed the effect of Al substitution on the electronic, magnetic, and optical properties of Ni3Mn intermetallics. We have calculated the coefficient of electronic specific heat, γ, for all these alloys; the values obtained are much larger compared to those in the constituent metals. We have found that the Al-doped Ni3Mn maintains the ferromagnetic character and leads to a decrease in the local and total magnetic moments but improves the conductivity. Qualitatively, the line shape of the theoretical optical conductivity coincides well with the experimental data. The magnetic moments per formula unit are found to be in good agreement with observed theoretical and experimental values.

Full text

J Supercond Nov Magn (2016) 29:1665–1674
DOI 10.1007/s10948-016-3453-y
ORIGINAL PAPER
First-Principles Study of Electronic, Magnetic, and Optical
properties of the Intermetallic Compounds Ni3Mn Doped
with Al
Latifa Mezhoudi1·Athmane Meddour1
Received: 2 February 2016 / Accepted: 3 February 2016 / Published online: 18 February 2016
© Springer Science+Business Media New York 2016
Abstract In this paper, we have calculated the electronic,
magnetic, and optical properties of Ni3Mn1−xAlx(x=0,
0.25, 0.50, 0.75), using a spin-polarized scalar relativistic
linear muffin-tin orbital (SPR-LMTO) method within den-
sity functional theory (DFT). The spin–orbit coupling was
included as a perturbation in the self-consistent iterations.
In our calculations for densities of states, we have used in
all alloys the energy (E) range from −10 to +10 eV. And
for the optical spectra in all alloys, we have used the same
energy range from 0.083 to 5.640 eV. In this work, we have
discussed the effect of Al substitution on the electronic,
magnetic, and optical properties of Ni3Mn intermetallics.
We have calculated the coefficient of electronic specific
heat, γ, for all these alloys; the values obtained are much
larger compared to those in the constituent metals. We have
found that the Al-doped Ni3Mn maintains the ferromag-
netic character and leads to a decrease in the local and total
magnetic moments but improves the conductivity. Qualita-
tively, the line shape of the theoretical optical conductivity
coincides well with the experimental data. The magnetic
moments per formula unit are found to be in good agreement
with observed theoretical and experimental values.
Keywords Ni3Mn ·Intermetallics ·Magnetism ·
Conductivity
Latifa Mezhoudi
mezhoudilatifa@gmail.com
1Materials Physics Laboratory, 8 May 1945 Guelma University,
P.O. Box 401, 24000 Guelma, Algeria
1 Introduction
Intermetallics is the short and summarizing designation
for the intermetallic phases and compounds which result
from the combination of different metals and which form a
vastly numerous and manifold class of materials [1]. Some
intermetallics are interesting functional materials; others
have attracted attention as structural materials for high-
temperature applications. They are used in a wide range of
industries such as semiconductors, superconductors, and the
aerospace industry [2]. Intermetallics with the L12struc-
ture have been the subject of more research over recent
decades because they are considered technologically impor-
tant owing to the interesting chemical, mechanical, and
physical properties. Some studies dealing with the L12
structure have been published in Refs. [2–12].
Nickel forms intermetallic phases with an L12structure
and the composition Ni3X, where X is either an element
near Al in the periodic table or another transition metal
near Ni, e.g., Mn [1]. The L12-type ordered Ni-based inter-
metallics, Ni3Mn, has been an attractive example of such
alloys and can undergo a structural phase transition, where
the magnetic behavior is sensitive to the atomic arrangement
[7]. Since Kaya and Kussman [10] discovered ferromag-
netism in these alloys, several studies have been reported.
The ordered Ni3Mn alloy is ferromagnetic at Curie tem-
perature TC≈733 K [3,11]. The spontaneous mag-
netic moments of Ni and Mn atoms in Ni3Mn alloy are
μNi0.3μB/Ni and μMn ∼3.6μB/Mn [3,12].
To our knowledge, some alloys can be improved by
adding another element. That is why, in this work, we are
interested in studying the ternary Ni3Mn-based alloys doped
by a poor metal (aluminum 3p-block). For the reason that,
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