Orthorhombic structure stabilazation in bulk HfO2 by yttrium doping

Banerjee, Debashis; Dey, C.C.; Sewak, R.; Thakare, S. V.; Toprek, Dragan

doi:10.1007/s10751-021-01765-z

Cited by 4 publications

(1 citation statement)

References 26 publications

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“…Several DFT studies reported the change in relative phase stability due to tetravalent and aliovalent , doping in HfO 2 . Clima et al reported the reduced polarization switching energy barrier in Si-doped HfO 2 , but the polarization switching pathway was via the Pbcm phase instead of the P 4 2 / nmc phase .…”

Section: Introductionmentioning

confidence: 99%

Tetravalent Doping in Fluorite-Based Ferroelectric Oxides for Reduced Voltage Operations

Chae

Kummel

Cho

2022

ACS Appl. Mater. Interfaces

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First-principles calculations show a reduced energy barrier for polarization switching via a bulk phase transition by doping of hafnium−zirconium oxide (HZO). The tetragonal P4 2 / nmc phase serves as a transition state for polarization switching of the polar orthorhombic Pca2 1 phase. Due to the high symmetry of the tetragonal phase, dopants can form more energetically favorable local oxygen bonding configurations in the tetragonal phase versus the orthorhombic phase. Significant bond strain is observed in the orthorhombic phase due to the low symmetry of the host crystal structure which decreases the relative stability of the doped orthorhombic phase compared to the doped tetragonal phase, thereby significantly lowering the barrier for switching but slightly affecting the polarization of the orthorhombic phase. Si is a promising dopant for an efficient ferroelectric device with minimal disturbance in the electronic structure parameters. Ge doping is suitable for stabilizing the tetragonal phase which shows a high k value.

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