NiMn-Based Metamagnetic Shape Memory Alloys

Abstract

Abstract. The magnetic properties of the parent and martensite phases of the Ni 2 Mn 1+x Sn 1-x and Ni 2 Mn 1+x In 1-x ternary alloys and the magnetic field-induced shape memory effect obtained in NiCoMnIn alloys are reviewed, and our recent work on powder metallurgy performed for NiCoMnSn alloys is also introduced. The concentration dependence of the total magnetic moment for the parent phase in the NiMnSn alloys is very different from that in the NiMnIn alloys, and the magnetic properties of the martensite phase with low magnetization in both NiMnSn and NiMnIn alloys has been confirmed by Mössbauer examination as being paramagnetic, but not antiferromagnetic. The ductility of NiCoMnSn alloys is drastically improved by powder metallurgy using the spark plasma sintering technique, and a certain degree of metamagnetic shape memory effect has been confirmed. IntroductionSince Ullakko et al. [1] first reported a magnetic field-induced strain (MFIS) in a ferromagnetic single crystal of Ni 2 MnGa in 1996, the research in this field has drastically progressed and a huge MFIS of over 9% [2] has recently been reported. The MFIS in the Ni 2 MnGa alloys, however, is not due to the shape memory effect (SME) accompanying martensitic transformation, but rather to rearrangement of martensite variants by twin boundary migration in the martensite (M) phase. This twin boundary migration induced by a magnetic field is caused by the large crystalline magnetic anisotropy energy of the M phase with low crystal symmetry. Details on the MFIS in the Ni 2 MnGa alloys have recently been reviewed by Marioni et al. [3]. Although a large output strain and a rapid response can be confirmed in the Ni 2 MnGa alloy, the output stress is principally less than 5 MPa [4]. Furthermore, significant brittleness of the Ni 2 MnGa single crystal is a serious problem preventing application of this material. On the other hand, some trials using phase transformation itself to obtain an MFIS have been reported [5][6][7]. In Ni 2 MnGa alloys, however, a huge magnetic field is required to obtain magnetic field-induced transformation because both the P and M phases show ferromagnetism and the saturated magnetization of the M phase is comparable to that of the P phase [8]. Up to now, many Ni-based magnetic shape memory alloys (MSMAs) with similar magnetic properties, such as NiMnAl [9,10], NiCoAl [11,12], NiCoGa [12,13], NiFeGa [14,15], etc., have been reported and the characteristic features of their magnetic and martensitic transformations have been clarified.Recently, we have found an unusual transformation from a ferromagnetic P to a weak magnetic M phase in the NiMnIn-and NiMnSn-based Heusler alloys [16], which shows behaviors completely different from the previous MSMAs. These new types of magnetic shape memory alloys show many interesting phenomena derived from the unique transformation, such as magnetic field-induced phase transition, the inverse magnetocaloric effect [17,18], the giant magnetoresistance effect [19,20], giant

Effect of Crystalline Structure on Some Physical Properties of Bulk and Thin Film Ni$_{50}$Mn$_{35}$In$_{15}$ Alloy Samples

“…Встановлено, що сплави Ni 2 Mn 1+x In 1−x з 0 < < x ≤ 0,32 є феромагнетиками зі структурою L2 1 . В сплавах Ni 2 Mn 1+x In 1−x з 0,32 ≤ x ≤ 0.6 спостерігається мартенситне перетворення (МП), при якому аустенітна кубічна L2 1 -фаза при зменшенні температури перетворюється в немагнітну мартенситну фазу з тетрагональною, орторомбічною чи моноклінною структурами [2]. Пряме МП супроводжується також різким значним зростанням електроопору [3][4][5].…”

“…рис. 9), що температурні залежності ефективної намагніченості для аморфних та кристалічних впорядкованих по типу L2 1 (2). Вкладка наводить у збільшеному форматі ділянку залежності ρ(Т) перед кристалізацією плівок.…”

“…In-plane magnetization hysteresis loops for amorphous(1) and crystalline(2) Ni 43 Mn 32 In 25 alloy films. між атомами Mn змінюється з феромагнітної на антиферомагнітну.…”

Ni50Mn36Sn14 Heusler Alaşımının Yumuşak Manyetik Karakteri

“…The cytotoxicity and ion release from an Ni50Mn36Sn14 atomic percent composition meta-magnetic shape memory alloy were evaluated using NIH/3T3 fibroblasts [22]. The magnetic properties of the parent and martensite phases of Ni2Mn1+xSn1-x and Ni2Mn1+xIn1-x and the magnetic field-induced shape memory effect obtained in NiCoMnIn alloy were reported [23]. The martensitic transition and magnetic entropy change of the Ni51Mn49-xSnx were searched for [24].…”

High-field magneto-thermo-mechanical testing system for characterizing multiferroic bulk alloys

“…NiMnX alloy systems, where X is In, Sn, Sb, and Al are the most widely recognized MMSMAs. [15][16][17][18] MMSMAs undergo simultaneous thermoelastic (martensitic) and magnetic phase transitions. The martensitic phase transformation in MMSMAs is the result of a reversible change in crystal structure and is accompanied by a large recoverable shape change.…”