相关论文: Sub-nanosecond structural dynamics of the martensi…
Structural martensitic transformations enable various applications, which range from high stroke actuation and sensing to energy efficient magnetocaloric refrigeration and thermomagnetic energy harvesting. All these emerging applications…
Shape memory alloys have a wide range of applications, including high stroke actuation, energy-efficient ferroic cooling, and energy harvesting. These applications are based on a reversible martensitic transformation, which results in a…
Ni-Mn-Ga films in the austenite and the martensite structures at room temperature have been obtained using the DC magnetron sputtering technique. Two elaboration processes were studied. A first batch of samples was deposited using a resist…
Martensitic transformations are strain driven displacive transitions governing the mechanical and physical properties in intermetallic materials. This is the case in Ni$_2$MnGa, where the martensite transition is at the heart of the…
Homogeneous freestanding films have been obtained by the direct current (DC) magnetron sputtering technique using a sacrificial layer. After annealing, the films are crystallized with a strong out-of-plane texture along the (022) direction.…
The optical and magneto-optical properties of thin epitaxial Ni-Mn-Ga films, with thicknesses ranging from 8 to 160 nm, were investigated across the spectral range of 0.7-6.4 eV. The films were deposited by DC magnetron sputtering on MgO…
The reverse martensitic ("austenitic") transformation upon heating of equiatomic nickel-titanium nanoparticles with diameters between 4 and 17 nm is analyzed by means of molecular-dynamics simulations with a semi-empirical model potential.…
We report magnetization and differential thermal analysis measurements as a function of pressure accross the martensitic transition in magnetically superelastic Ni-Mn-In alloys. It is found that the properties of the martensitic…
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 a broadband ferromagnetic resonance study in single crystalline Ni$_{50}$Mn$_{28.1}$Ga$_{21.9}$ in the temperature range from room temperature to 120 {\deg}C in which the transformation from martensite to austenite phase takes…
Besides permitting an accurate determination of the ferromagnetic-to-paramagnetic phase transition temperature and the characteristic temperatures for the beginning and end of the growth of martensite (austenite) phase at the expense of…
Shape memory alloys like NiTi are at the core of emerging thermal management applications, including elastocaloric refrigeration, thermoelastic harvesting, and latent heat storage. Most of these applications benefit from a small scale due…
A systematic study of magnetic properties of Ni2+xMn1-xGa (0 \le x \le 0.19) Heusler alloys undergoing structural martensite-austenite transformations while in ferromagnetic state has been performed. From measurements of spontaneous…
In search for the origins of the extraordinary low twinning stress of Ni-Mn-Ga magnetic shape memory alloys we studied the thermally induced changes of structure in Ni$_{50}$Mn$_{25+x}$Ga$_{25-x}$ ($x$=2.7--3.9) single crystal samples and…
Ferromagnetic shape memory alloys Ni$_{2+x}$Mn$_{1-x}$Ga were studied in the range of compositions $0.16 \le x \le 0.36$. Experimental phase diagram, constructed from differential scanning calorimetry, transport and magnetic measurements,…
We study the thermal properties of a bulk Ni55Fe19Ga26 Heusler alloy in a conduction calorimeter. At slow heating and cooling rates (1K/h), we compare as-cast and annealed samples. We report a smaller thermal hysteresis after the thermal…
We present here results of temperature dependent high resolution synchrotron x-ray powder diffraction study of sequence of phase transitions in Ni2MnGa. Our results show that the incommensurate martensite phase results from the…
A laser-ultrasonic approach was used to measure elastic properties of a superelastic nickel-titanium wire with the aim to evaluate their evolution with stress and temperature in stress-induced martensite. It was observed that this evolution…
The identification and use of reversible Martensitic transformations, typically described as shape memory transformations, as a new class of solid-solid phase change material is experimentally demonstrated here for the first time. To prove…
The inverse magnetocaloric effect (MCE) in Ni-Mn-based Heusler compounds occurs during the magnetostructural transition between low-temperature, low-magnetization martensite and high-temperature, high-magnetization austenite. In this study,…