Structural and chemical features of Gd:BaTiO$_3$ solid solutions prepared by microwave-assisted heat treatment
HAN-SOL YUN JAE-HYEON SHIM YONG-SEON KIM SU-YEON KIM SO-YOUNG SHIN KWON-JIN PARK CHUN-YEOL YOU DAE-YONG JEONG NAM-HEE CHO
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Herein, Gd-doped BaTiO$_3$ (Gd:BTO) solid-solution powders were prepared by microwave-assisted heat treatment (MWH). The structural and chemical characteristics of the powders were analysed by scanning transmission electron microscopy and electron energy loss spectroscopy. The defect formation reactions relevant to Gd doping are discussed based on the change in the electron energy structure as well as the density functional theory calculations. Ba(OH)$_2$.H$_2$O, TiO$_2$.4H$_2$O and Gd(NO$_3)_3$.6H$_2$O were used as Ba, Ti and Gd precursors, respectively. A Ba/Ti mole ratio of 1.2 in the precursor at a reaction temperature of 300°C was determined to be the optimal synthetic conditions for preparing the Gd:BTO solid solution. Gd evidently occupied the Ti sites (denoted as $Gd_{Ti}$) of BaTiO$_3$ structure, and the substitution of Ti with Gd was accompanied by a change in the oxidation state of the Ti ions and the generation of oxygen vacancies. The magnetic susceptibility of the Gd:BTO powders increased with increase in concentration of $Gd_{Ti}$ with unidirectional electron spins. In contrast, the relative dielectric constant varied inversely with the Gd concentration owing to the evolution of oxygen vacancies and lattice distortion of the Gd:BTO powders with the increase in the Gd concentration.
HAN-SOL YUN1 JAE-HYEON SHIM2 YONG-SEON KIM1 SU-YEON KIM1 SO-YOUNG SHIN1 KWON-JIN PARK3 CHUN-YEOL YOU3 DAE-YONG JEONG1 NAM-HEE CHO1
Volume 45, 2022
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Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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