Dielectric Response of KTaO3 Single Crystals Weakly Co-Doped with Li and Mn

Alexander Tkach,Paula M. Vilarinho,Sebastian Zlotnik

doi:10.3390/cryst11101222

Alexander Tkach, Paula M. Vilarinho + Show 1 more

Open Access

https://doi.org/10.3390/cryst11101222

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Journal: Crystals	Publication Date: Oct 10, 2021
Citations: 4	License type: CC BY 4.0

Affiliation: University of Aveiro, Universiti Teknologi MARA

Abstract

Alkali tantalates are encouraging functional materials with versatile properties that make them potential players in microelectronics, photocatalytic processes or medicine. Here, KTaO3 single crystals with 0.27% Li and 0.15% or 0.31% Mn contents determined by inductively coupled plasma spectroscopy analysis are studied at low temperatures using dielectric spectroscopy in a frequency range of 102–106 Hz. Both Li and Mn doping are found to induce separate low-frequency dielectric relaxations of comparable strength in KTaO3. The relaxation dynamics follow the Arrhenius law with activation energy values of ~77 and 107 meV, attributing the relaxation origin to the dipoles formed by off-centre Li+K and Mn2+K ions, respectively.

Highlights

Alkali tantalates, such as KTaO3 (KT) and LiTaO3, are members of the ferroic family of lead-free compounds with potential applications for electronic components and tissue engineering, respectively [1]
Their solid solution K1–x Lix TaO3 has been intensively studied, wherein displacements of small Li ions on K sites generate strong local dipole moments, which couple electrostatically to the KT polar soft mode [2,3]. Both dielectric relaxations and ferroelectric phase transition were reported for heavily Li-doped KT
The dielectric relaxation was reported in weakly (0.01–0.3%) Mn-doped KTaO3 single crystals [11,12,13]

Summary

Introduction

Alkali tantalates, such as KTaO3 (KT) and LiTaO3 , are members of the ferroic family of lead-free compounds with potential applications for electronic components and tissue engineering, respectively [1] Their solid solution K1–x Lix TaO3 has been intensively studied, wherein displacements of small Li ions on K sites generate strong local dipole moments, which couple electrostatically to the KT polar soft mode [2,3]. As a result, both dielectric relaxations and ferroelectric phase transition were reported for heavily Li-doped KT.

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