TITLE:
Antiferroelectricity in ZrO2 and Ferroelectricity in Zr, Al, La Doped HfO2 Nanoparticles
AUTHORS:
A. T. Apostolov, I. N. Apostolova, J. M. Wesselinowa
KEYWORDS:
ZrO2 Nanoparticles, Zr, Al, La Doped HfO2 Nanoparticles, Electric Properties, Microscopic Model, Green’s Function
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.10 No.2,
February
21,
2020
ABSTRACT: The dependence of the
polarization P in Hf1-xZrxO2 nanoparticles on electric field, dopant
concentration x, size and temperature
are studied using the transverse Ising model and the Green’s function method.
Pure ZrO2 shows at high electric fields an antiferroelectric
behavior. Pure HfO2 is a linear dielectric in the monoclinic phase.
With increasing ZrO2 content the of HZO shows a
ferroelectric behavior. The composition dependence x of the remanent polarization Pr(x)has a maximum for x = 0.5. For x = 0, pure HfO2, and x = 1, pure ZrO2, Pr=0. P increases with
decreasing HZO nanoparticle size. The influence of Al and La doping on Pr in HfO2 nanoparticles is also studied. The exhibiting of the ferroelectricity in ion
doped HfO2 is due to a phase transformation and to an internal
strain effect. The observed results are in good qualitative agreement with the
experimental data.