... indentation is given by P = k1dn, where ‘k1’ is the material constant, ‘n’ is the Meyer's index
or work hardening coefficient19,20.
The plot of log P against log d is shown in Fig. 6b, which gives a straight line (after
least square fitting), from which the value of ‘n’ for ZnSO4.H2O, glycine and ZS ...