Electrocaloric response of KNbO3 from a first-principles effective Hamiltonian

• It is the first time that the electrocaloric response of KNbO3 is reported.
• The results are explained in terms of the bonding by comparing KNbO3 to BaTiO3, which is a well-studied compound.
• The results are well represented by a regression that allows for their application to engineering projects.

The electrocaloric response of KNbO3 is calculated using a first-principles based effective-Hamiltonian. Both indirect and direct molecular dynamics simulations are used to determine the adiabatic temperature change as a function of temperature and applied electric field. Both the magnitude of the electrocaloric response, ΔTmax, and the temperature where the maximum is observed, T*, are comparable for both molecular dynamics approaches. The results are well represented by a simple second-order regression.