Nanoindentation pop-in effects of Bi2Te3 thermoelectric thin films

Mechanical properties of Bi2Te3 topological insulator investigated by density functional theory and nanoindentation

“…For the perpendicular direction (top panel), the hardness stabilizes around 1.7 GPa whereas its saturation value is about 0.9 GPa in the parallel direction (bottom panel). As observed for the Bi 2 Te 3 thin films [55], the hardness has an initial increase at small penetration depth, attributed to the transition between purely elastic to elastic/plastic contact, and a following decrease until a stabilized value, related to the transition between elastic/plastic and fully plastic contacts. Until the fully plastic contact is not reached, the measured hardness is actually reflecting the mean contact pressure and it does not represent the intrinsic hardness of the material.…”

The dimensional crossover of quantum transport properties in few-layered Bi2Se3 thin films

“…[33][34][35] To obtain a greater transport contribution from the topological SS, it is important to obtain TI thin lms with a high crystallization quality. The methods usually used for preparing TI thin lms include molecular beam epitaxy (MBE), 33,[36][37][38][39][40] chemical vapor deposition, [41][42][43][44] physical vapor deposition, [45][46][47][48] pulsed laser deposition (PLD) [49][50][51][52][53][54][55][56][57][58][59][60] and sputtering. 61,62 The MBE is the method mainly used to obtain at and thin TI lms for fundamental research, because of its advantages of 2D growth, single crystal yield and easily controlled doping.…”

Localized Deformation and Fracture Behaviors in InP Single Crystals by Indentation

“…Within the dominant deformation mechanism in the context of dislocation, the multiple “pop-ins” (indicated by the arrows in Figure 1a) can be regarded as the trigger of sudden collective activities of dislocation [29,30,31] (such as dislocation generation or movement bursts), giving rise to the seemingly discontinuous plastic deformation during nanoindentation. Such massive dislocation activities are also consistent with the conjectures of the resultant “noisy” features seen in the depth-dependent curves of hardness and Young’s modulus (Figure 1b,c), as well as those reported by Almeida et al [32] and Jian et al [22].…”