Electronic Contributions to Ferroelectricity and Field-Induced Phase Transitions in Doped-HfO2

摘要

Causes for the emergence of ferroelectricity and field-induced phase transitions in doped HfO2, Hf1-xZrxO2, and ZrO2 are a rich topic of scientific debate for these important technological materials. A phenomenological framework that can explain the most pertinent features of ferroelectricity and phase transitions with doping and composition remains conspicuously absent, despite much insight generated from ab initio and DFT calculations. From the Landau theory of phase transitions, it is shown that electronic and bonding contributions from dopants can directly impact the formation of the ferroelectric phase. The size of the dopant ions and the appearance of field-induced phase transitions are found to be inextricably linked.