Sensitec: Control of strain in magnetoresistive elements and its utilization

Host: Sensitec GmbH

PHD enrolment: Johannes Gutenberg University Mainz

Location: Mainz, Germany

Supervisor: Ronald Lehndorff

Scientific project:

Magnetoresistive (MR) sensors consist of magnetic thin films and micro- to nanostructures. It is important to understand the behaviour of magnetic domain walls in these structures, to be able to optimize the performance of the sensors. Strain or mechanical stress is, up to now, always seen as a negative impact on MR sensors. In this project, the influence of strain on MR sensor will be studied with two aspects. On the one hand, the conventional approach of minimizing the sensitivity of the sensor to strain by means of design and choice of materials will be pursued. On the other hand, the utilization of strain to realise new or improved functionalities will be a goal.

Manipulating domain walls, specifically creating, annihilating, pinning or guiding them is of great interest. These basic functionalities can be the building blocks of domain wall based MR sensors or other devices like logic circuits. Different goals within this project are:

  • designing test structures to study the different functionalities under strain
  • preparing samples from sputter deposition of magnetic thin films, through lithography, up to bonding and soldering them to test stands
  • defining and performing test routines
  • analysing test results and applying theory and micromagnetic simulations to understand the physics of domain walls under strain