|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Nix Award and Lecture Symposium: Recent Advances in Nanoindentation and Small-Scale Mechanical Testing
||Size Effects in the Plastic Deformation and Fracture of Strontium Titanate
||Karsten Durst, Javaid Farhan, Xufei Fang
|On-Site Speaker (Planned)
Strontium titanate, SrTiO3, is one of the functional oxides which, in its single crystalline form, can undergo macroscopic plastic deformation even at room temperature, unlike other typical oxide ceramics. This makes STO an interesting model material for understanding the deformation mechanism of functional oxides, which are the basis for various advanced electronic devices. Here, size effects in plasticity and fracture are investigated using nanoindentation tests with Berkovich and spherical indenters in combination with sequential polishing, chemical etch pit techniques and high-resolution electron backscatter diffraction to quantify the geometrically necessary and total dislocation densities within the plastic zone of the indenter. Nanoindentation load-displacement curves show multiple pop-in events related to nucleation and expansion of dislocation pile-up around indentations, followed by nucleation of cracks. In the presentation, we will discuss the dislocation mechanism leading to different indentation size effects for spherical and Berkovich indentation.
||Mechanical Properties, Other, Other