  Sign and magnitude of the thermodynamic curvature provides empirical
information about the nature of microstructures of a general thermodynamic
system. For charged black holes in AdS, thermodynamic curvature is positive for
large charge or chemical potential, and diverges for extremal black holes,
indicating strongly repulsive nature. We compute the thermodynamic curvature at
low temperatures, for charged black holes with AdS$_2$ near horizon geometry,
and containing a zero temperature horizon radius $r_h$, in a spacetime which
asymptotically approaches $AdS_D$ (for $D>3$). In the semi-classical analysis
at low temperatures, the curvature shows a novel crossover from negative to
positive side, indicating the shift from attraction to repulsion dominated
regime near $T=0$, before diverging as $1/(\gamma T)$, where $\gamma$ is the
coefficient of leading low temperature correction to entropy. Accounting for
quantum fluctuations, the curvature computed in the canonical ensemble is
positive, whereas the one in the grand canonical ensemble, continues to show a
crossover from negative to positive side. Moreover, the divergence of curvature
at $T=0$ is cured irrespective of the ensemble used, resulting in a universal
constant.
