Self-Similarity in Magnetostrictive Materials: An Experimental Point of View

Magnetostrictive behavior is characterized by a complex coupling between magnetic and mechanical quantities. While this behavior can be quite easily exploited for both actuation and sensing or energy conversion purposes, the complex hysteresis interaction between magnetization and magnetic field and mechanical stress and strain is hard to model. Nevertheless, magnetic and magnetostrictive experimental curves are quite self-similar, assuming stress as self-similarity parameter. The quantification of this concept would help modeling. Here, this concept is quantified and experimentally confirmed over different types of magnetostrictive samples.

Effect of Graphene Thin Layer on a Static and Dynamic Magnetostrictive Behavior in TbDyFe Multi-Layered Film for Micro Energy Devices

Magnetos-mechanical behaviors of TbDyFe/Graphene/TbDyFe film were compared with a tri-layered TbDyFe film to verify the effects of a graphene thin layer on the improvement of magnetic-mechanical performance, as well as decrease of dynamic response time under the low magnetic field. Both of the Heisenberg model and Landau-Lifshitz-Gilbert equation were used to calculate the magnetic domain motion. Time consumptions were simulated to determine a uniformly magnetized state in Graphene and TbDyFe layers. To ensure the magnetostrictive characteristics, the magnetic moment and the magnetostriction were measured using a fabricated magnetostrictive actuator. Compare to the three-layer TbDyFe films, TbDyFe/Graphene/TbDyFe showed a higher magnetostrictive behavior in response to low coercive forces in the range of 0 to 10 kA/m, even with the addition of low magnetic fields. The dynamic magnetostriction response time was faster than the tri-layered TbDyFe film by approximately 24 millisecond.