Stable magnetostructural coupling with tunable magnetoresponsive effects in hexagonal ferromagnets

Abstract

The magnetostructural coupling between the structural and the magnetic transition has a crucial role in magnetoresponsive effects in a martensitic-transition system. A combination of various magnetoresponsive effects based on this coupling may facilitate the multifunctional applications of a host material. Here we demonstrate the feasibility of obtaining a stable magnetostructural coupling over a broad temperature window from 350 to 70 K, in combination with tunable magnetoresponsive effects, in mnniGe:Fe alloys. The alloy exhibits a magneticfield-induced martensitic transition from paramagnetic austenite to ferromagnetic martensite. The results indicate that stable magnetostructural coupling is accessible in hexagonal phasetransition systems to attain the magnetoresponsive effects with broad tunability.

Structural and magnetic properties of MnCo 1−x Fe x Si alloys

“…For 4 samples with x ≤ 0.50, the T m decreases nearly linearly from 1131 K to about 823 K (x=0.50) with increasing x. This decrease may be attributed to the strengthening of the covalent bonding induced by Fe atoms in MnCo 1-x Fe x Si, which is similar to the case in MnNi 1-x Fe x Ge alloys analyzed by the valence-electron localization function (ELF) [4]. As the substitution level of Fe for Ni (2d sites) in MnNiGe increases, the strengthened covalent bonding improves the stability of the parent phase and consequently decreases the martensitic transformation temperature.…”

“…In recent years, the magnetic hexagonal MM'X (M, M' = transition metals, X = carbon or boron group elements) alloys [1] have drawn increasing attention due to their remarkable magnetoresponsive properties, such as magnetic-field-induced martensitic transformation [2][3][4][5], giant magnetocaloric effect [3,4,[6][7][8][9], magnetoresistance [10] and magneto-strain [11,12]. It is therefore of interest for the smart applications and explorations of new functional materials.…”

Determination of hyperfine fields and atomic ordering in NiMnFeGe exhibiting martensitic transformation

“…Moreover, it was shown that the spiral structure changes to canted ferromagnetic one under applied high-magnetic fi eld and magnetization of the NiMnGe system saturate at about 10 T [6]. Substitution of Ni atoms by Fe allows controlling both the martensitic structural transition temperature and magnetic state of material [2]. All these studies indicate instability of the antiferromagnetic spiral structure and allow enhancement of the magnetoresponsive properties.…”

“…The magnetostructural coupling plays a crucial role in magnetoresponsive effects in systems with martensitic transitions and because of shape memory, magnetocaloric and magnetoresistance effects [1][2][3][4][5] leads to practical applications. One class of the materials exhibiting martensitic transformations is based on ternary alloys (MM'X, M,M' -transition metal, X -Si, Ge, Sn) with hexagonal Ni 2 In-type structure.…”

The study of crystal and magnetic properties of MnNi0.85Fe0.15Ge

“…The materials with stable magnetostructural coupling between the structural and the magnetic transition over a broad-temperature region from 70 to 350 K in combination with tunable magnetoresponsive effects are extremely interesting for a practical use. Recently, the possibility to obtain such a combination of properties has been shown for MnNiGe:Fe alloys [1,2].…”