Compósitos ferromagnéticos de PDMS e Liga Heusler Ni44Mn44Sn9Cu3

Abstract

Heusler Ni-Mn-Sn alloys have been widely studied because they present multifunctional properties associated with phase transitions controlled by the magnetic field, such as the metamagnetic shape memory effect, the magnetocaloric effect and exchange polarization. These properties are promising for applications such as magnetic actuators, magnetic refrigeration and high-efficiency sensors. Changing the composition by replacing its components with a fourth element, such as Cu, is an effective way to adapt their properties. However, these materials have limitations such as low machinability, mechanical brittleness and instability of functional properties after processing. To overcome these problems, a strategy involves the production of polymer matrix composite materials reinforced with these metal alloys. In this work, PDMS matrix composites reinforced with Heusler Ni44Mn44Sn9Cu3 alloy particles were produced. The developed materials showed preservation of the polymer chemical structure, thermal stability, reduction of mechanical resistance with the addition of metallic particles, greater flexibility compared to pure Heusler alloys, increase of remanent magnetization and saturation magnetization according to the increase of the alloy content, resulting in improvement of the ferromagnetic response. Thus, the results obtained indicate that the developed composites are favorable candidates for use in flexible devices that require tunable magnetic properties.