Fig. 4: Poisson’s ratio of metal halides under large tensile uniaxial strain along x-direction.
From: Auxetic two-dimensional transition metal selenides and halides
The general trend is that the Poisson’s ratio becomes more negative with larger strain along x-direction until reaching a minimum. In the extremely large strain regime, the further increase of uniaxial strain leads to an increase in the Poisson’s ratio. The estimated critical M1-X-M2 angles at which the Poisson’s ratios reach the minima are shown in the inset.
