TOPEventsSeminarsVolodymyr Chernenko (University of Basque Country): Recent developments in particulate Heusler type magnetic shape memory hybrid materials for actuation and energy
Seminars

Volodymyr Chernenko (University of Basque Country): Recent developments in particulate Heusler type magnetic shape memory hybrid materials for actuation and energy

VBL 204 and Zoom

Recent developments in particulate Heusler type magnetic shape memory hybrid materials for actuation and energy

Volodymyr Chernenko
Basque Center for Materials, Applications and Nanostructures and University of Basque Country, Leioa 48940, Spain

Heusler type magnetic shape memory alloys (MSMAs) are multifunctional materials exhibiting “giant” properties in the vicinity of the martensitic phase transition (MT), particularly, magnetic field induced strain and magnetocaloric effect. These materials can be conventionally divided into two groups: ferromagnetic shape memory alloys (FSMAs), such as prototype Ni-Mn-Ga compounds, and the metamagnetic shape memory alloys (MetaMSMAs), such as Mn-rich Ni-Mn-X (X=In, Sn, Sb). Both types of materials are capable to convert effectively the magnetic energy into mechanical (magnetic actuation) or caloric signal (magnetic cooling) and reversely the thermal and/or elastic energy into an electromagnetic signal, which is promising for application in novel transducers and sensors. To prevent the inherent fragility of MSMAs materials, we have created their particulate hybrids with novel characteristics. In contrast to bulk Ni-Mn-Ga microparticles are technologically and costly more efficient. They have much higher degree of freedom in terms of composites design allowing the development of advanced miniature actuators and sensors. We will showcase the latest developments in MSMA particles containing hybrid materials.

  1. We will present the innovative NiMnGa particles/polymer composites that exhibit a remarkable rubber-like response to magnetic fields: under a periodic magnetic field of several kOe the composite can repeatedly deform by 4%. The underlying mechanism of this response has been elucidated through X-ray micro-CT.
  2. We found that thin film composites containing NiMnGa particles distributed in the P(VDF-TrFE) piezopolymer exhibit an unprecedented resonance amplification of the magnetoelectric (ME) signal in both martensitic and austenitic states of particles. The physical mechanism of the ME response amplification has been disclosed theoretically.
  3. We have elaborated laminated composites comprising a layered ensemble of single crystalline Ni-Mn-Ga particles built-in between Cu foils via thin layers of silicone rubber. Such a robust design enabled a detailed investigation of the simultaneous influence of the magnetic field and compressive opposing stress on a giant magnetic field induced strain and the generated force of the particle layer driving out-of-plane stroke of laminate. A significantly improved magnetostrain response of the laminate composite was achieved after replacing the Cu foils with soft-magnetic Fe foils.
  4. A new route for the room-temperature fabrication of the magnetocaloric ink incorporating the polymer binder and Ni(Co)-Mn-Sn MetaMSMA particles was elaborated. The ink was used to print 2D films which do not require a subsequent heat treatment. The field-induced adiabatic temperature measurements reveal that the screen- printed samples displayed the same inverse magnetocaloric effect as the ribbon, which was used to prepare particles.

Zoom Information:

https://us02web.zoom.us/j/2022111100

(Meeting code: 2022111100 Password: skcm2)

Back to List

pagetop