Multi-field nanoindentation apparatus for measuring local mechanical properties of materials in external magnetic and electric fields

TL;DR

This paper introduces a novel modular multi-field nanoindentation apparatus capable of measuring local mechanical properties of materials under external magnetic and electric fields, revealing field-induced coupling effects.

Contribution

It presents the first construction of a multi-field nanoindentation device for testing materials in external magnetostatic and electrostatic fields, addressing key technical challenges.

Findings

Feasibility demonstrated through calibration tests.

Magnetic/electric fields induce measurable changes in elastic modulus.

Small-scale magnetomechanical and electromechanical coupling observed.

Abstract

Nano/micro-scale mechanical properties of multiferroic materials can be controlled by the external magnetic or electric field due to the coupling interaction. For the first time, a modularized multi-field nanoindentation apparatus for carrying out testing on materials in external magnetostatic/electrostatic field is constructed. Technical issues, such as the application of magnetic/electric field and the processes to diminish the interference between external fields and the other parts of the apparatus, are addressed. Tests on calibration specimen indicate the feasibility of the apparatus. The load-displacement curves of ferromagnetic, ferroelectric and magnetoelectric materials in the presence/absence of external fields reveal the small-scale magnetomechanical and electromechanical coupling, showing as the Delta-E and Delta-H effects, i.e. the magnetic/electric field induced changes in the apparent elastic modulus and indentation hardness.