Related papers: Shape memory ferromagnets
Current theoretical studies on structural and magnetic properties of functional Ni-Mn-Z (Z = Ga, In, Sn) Heusler alloys address the origin of the structural transition from the austenite to martensite, and also address the dominant…
We present our recent results on temperature behaviour of magnetization observed in Ni_47Mn_39In_14 Heusler alloys. Three regions can be distinguished in the M-T diagram: (I) low temperature martensitic phase (with the Curie temperature…
Shape memory materials have the ability to recover their original shape after a significant amount of deformation when they are subjected to certain stimuli, for instance, heat or magnetic fields. However, their performance is often limited…
The reorientation transition of the magnetization of ferromagnetic films is studied on a microscopic basis within Heisenberg spin models. Analytic expressions for the temperature dependent anisotropy are derived from which it is seen that…
We use phase field simulations to study composites made of two different ferroelastics (e.g., two types of martensite). The deformation of one material due to a phase transformation can elastically affect the other constituent and induce it…
A quantitative model describing large magnetostrain effect observed in several ferromagnetic shape memory alloys such as Ni2MnGa is briefly reported.The paper contains an exact thermodynamic consideration of the mechanical and magnetic…
Bulk metallic samples were synthesized from different binary powder mixtures consisting of elemental Cu, Co, and Fe using severe plastic deformation. Small particles of the ferromagnetic phase originate in the conductive Cu phase, either by…
The magnetostructural coupling between the structural and the magnetic transition plays a crucial role in magnetoresponsive effects in a martensitic-transition system. A combination of various magnetoresponsive effects based on this…
We demonstrate the magnetization reversal features in NiFe/IrMn/NiFe thin-film structures with 40% and 75% relative content of Ni in Permalloy in the temperature range from 80 K to 300 K. At the descending branches of the hysteresis loops,…
Shape memory alloys (SMAs) exhibit hysteresis behaviors upon stress and temperature induced loadings. In this contribution, we focus on numerical simulations of microstructure evolution of cubic-to-tetragonal martensitic phase…
Applying a magnetic field to a ferromagnetic Ni$_{50}$Mn$_{34}$In$_{16}$ alloy in the martensitic state induces a structural phase transition to the austenitic state. This is accompanied by a strain which recovers on removing the magnetic…
Modulated phases occur in numerous functional materials like giant ferroelectrics and magnetic shape memory alloys. To understand the origin of these phases, we review and generalize the concept of adaptive martensite. As a starting point,…
We have studied the magnetocaloric effect (MCE) in the shape-memory Heusler alloy Ni$_{50}$Mn$_{35}$In$_{15}$ by direct measurements in pulsed magnetic fields up to 6 and 20 T. The results in 6 T are compared with data obtained from…
It is of common knowledge that the direction of easy axis in the finite-size ferromagnetic sample is controlled by its shape. In the present paper we show that a similar phenomenon should be observed in the compensated antiferromagnets with…
The effects of magnetic field on the martensitic transition have been studied in Ni45Co5Mn38Sb12. We find a large field-induced irreversibility in this system, as revealed by the field dependence of resistivity, magnetization, and heat…
Nearly 30% increase of the ferromagnetic phase transition temperature has been achieved in strained MnAs nanocrystals embedded in a wurtzite GaAs matrix. Wurtzite GaAs exerts tensile stress on hexagonal MnAs nanocrystals, preventing a…
The martensitic and magnetic phase transformations in MnNiGe1-xSnx (0 \leq x \leq 0.200) alloys were investigated using X-ray diffraction (XRD), differential thermal analysis (DTA) and magnetization measurements. Results indicate that the…
We propose a method for modeling the magnetic properties of nanomaterials with different structures. The method is based on the Ising model and the approximation of the random field interaction. It is shown that in this approximation, the…
Functional behavior of NiTi shape memory alloys is restricted to temperatures below 150 {\deg}C. To shed light on the origin of the loss of functional properties of NiTi with increasing temperature, we have investigated stress induced…
We present studies of the magnetic domain structure of UMn$_2$Ge$_2$ single crystals using a home-built low temperature magnetic force microscope. The material has two distinct magnetic ordering temperatures, originating from the Mn and U…