Evaluation of mechanical hardness and fracture toughness of Co and Al co-doped ZnO

Assessing hardness and fracture toughness in sintered zinc oxide ceramics through indentation technique

“…The most common way to represent this property is by calculating the apparent hardness, H, from the applied load, P and indent diagonal, d. In case of a Vicker's indenter; it is determined from the load and the diagonal impression mark made by a standard geometrical indenter of defined shape using the relation [9]:…”

“…The nature of the crack can be identified by seeing the microscopic image of the indented samples. Median cracks show a tendency to remain attached to the corner of the indentation marks, whereas Palmqvist cracks show separation from the corner point [9,12]. Another way of identifying these two types of cracks is finding out the nature of the crack length variation with applied load.…”

“…ZnO based varistors show the potentiality for application in electronic circuits as surge absorbers for sudden high-voltage loads [7,8]. Dopant addition plays a vital role in governing the electrical, magnetic and optical properties of ZnO along with a correlated microstructure [9,10]. Keeping in mind the versatility of ZnO ceramics, mechanical property of undoped and doped ZnO samples is of important concern pertaining to its use of various devices ranging from environmental sensors to photo detectors, solar cells, varistors, piezo-electric devices etc.…”

“…Keeping in mind the versatility of ZnO ceramics, mechanical property of undoped and doped ZnO samples is of important concern pertaining to its use of various devices ranging from environmental sensors to photo detectors, solar cells, varistors, piezo-electric devices etc. [9,11].…”

Tuning selectivity through cobalt doping in spray pyrolysis deposited ZnO thin films

“…Among all, doping is the most effective and efficient way to tune the selectivity of the metal oxides [7,30,31]. The d-orbital occupation and electronic configurations of transition metals (Mn, Fe, Co, Ni and Cu) made them as the most suitable dopants to amend the electrical properties and morphology of the ZnO host [32][33][34][35]. The most common oxidation state of cobalt is Co 2 þ .…”