DFT Models of Negative Capacitance

Negative capacitance (or more properly negative differential capacitance) is thought to result from the electrostatic interaction between adjacent layers of a paraelectric and a ferroelectric. The key experimental signature of negative capacitance is a high dielectric constant but an atomic model for this phenomenon in Hf
_0.5
Zr
_0.5
O
₂
has not been established. Here, DFT calculations are shown which document a paraelectric layer inducing a phase instability in the ferroelectric HfO
₂
, consistent with negative capacitance.