To study the mechanical effect of the microprobe contact, we performed ex situ nanoindentation on polished LLZO using a spherical diamond tip with a diameter of 3.6 µm. The hysteresis in load-displacement curves shown in Figure indicates that plastic deformation may be occurring upon 5 mN contact. In addition, microfracture could also simultaneously occur upon loading, as commonly observed in many ceramics during wear and abrasion testing .