This paper intends to review the state-of-the-art in the field of ferromagnetic shape memory alloys different than Ni–Mn–Ga, developed in the ast years. It starts with the effects of additions of different fourth elements to Ni–Mn–Ga and continues with the review of other Heusler (or B2) i-based and Co-based alloy systems, like Ni–Mn–X, Ni–Fe–Ga, Co–Ni–Al and Co–Ni–Ga alloys. Finally, ferromagn...

Influence of disorder, antisite defects, martensite transition and compositional variation on the magnetic properties and electronic structure of Mn(2)NiGa and Mn(1+x)Ni(2-x)Ga magnetic shape memory alloys have been studied by using full potential spin-polarized scalar relativistic Korringa-Kohn-Rostocker (FP-SPRKKR) method. Mn(2)NiGa is ferrimagnetic and its total spin moment increases when di...

The magnetic shape memory (MSM) alloy Ni-Mn-Ga is an active material where large strains are obtained by magnetically induced reorientation (MIR) of martensitic variants. For the integration in microsystems, epitaxial thin films are in the centre of interest since the highest strains have only been obtained in single crystals. In order to minimize the technological effort, sputter deposition at...

The magnetic shape-memory alloy Ni-Mn-Ga shows, in monocrystalline form, a reversible magnetic-field-induced strain (MFIS) up to 10%. This strain, which is produced by twin boundaries moving solely by internal stresses generated by magnetic anisotropy energy, can be used in actuators, sensors and energy-harvesting devices. Compared with monocrystalline Ni-Mn-Ga, fine-grained Ni-Mn-Ga is much ea...

Foams with 55% and 76% open porosity were produced from a Ni-Mn-Ga magnetic shape-memory alloy by replication casting. These polycrystalline martensitic foams display a fully reversible magnetic-field-induced strain of up to 0.115% without bias stress, which is about 50 times larger than nonporous, fine-grained Ni-Mn-Ga. This very large improvement is attributed to the bamboolike structure of g...

The TA2 phonon dispersion curves of Ni-Mn-Ga alloys with different compositions which transform to different martensitic structures have been measured over a broad temperature range covering both paramagnetic and ferromagnetic phases. The branches show an anomaly (dip) at a wave number that depends on the particular martensitic structure, and there is softening of these anomalous phonons with d...

The complex magnetic and structural properties of Co-doped Ni-Mn-Ga Heusler alloys have been investigated by using a combination of first-principles calculations and classical Monte Carlo simulations. We have restricted the investigations to systems with 0, 5 and 9 at% Co. Ab initio calculations show the presence of the ferrimagnetic order of austenite and martensite depending on the compositio...

In this joint experimental and ab initio study, we focused on the influence of the chemical composition and martensite phase transition on the electronic, magnetic, optical, and magneto-optical properties of the ferromagnetic shape-memory Ni-Mn-Ga alloys. The polar magneto-optical Kerr effect (MOKE) spectra for the polycrystalline sample of the Ni-Mn-Ga alloy of Ni60Mn13Ga27 composition were me...

We report results of ab-initio calculations of the ferromagnetic Heusler alloy Ni-Mn-Ga. Particular emphasis is placed on the stability of the low temperature tetragonal structure with c/a = 0.94. This structure cannot be derived from the parent L21 structure by a simple homogeneous strain associated with the soft elastic constant C ′. In order to stabilise the tetragonal phase, one has to take...