Year: 2025
Type: article
Abstract: Co-doping at Ba and Ti sites with double rare-earth elements has proven an effective strategy for enhancing the dielectric properties of BaTiO3 ceramics. Among intermediate-sized rare-earth ions, Tb and Ho exhibit amphoteric behavior, occupying both Ba and Ti sites. Investigating the site occupation, defect chemistry, and dielectric effects of Tb and Ho in BaTiO3 is therefore valuable. In this work, Tb/Ho-co-doped BaTiO3 ceramics with the composition (Ba1−xTbx)(Ti1−xHox)O3 (x = 0.01~0.10) were fabricated at 1400 °C via solid-state reaction, and their solid solubility and crystal structures are confirmed. Microstructure, dielectric properties, photoluminescence, and valence states of samples with a single phase were systematically studied. Both the lattice parameter a and unit cell volume increase with doping level. The ceramic with x = 0.02 meets the X5S dielectric specification. Ho and Tb ions both demonstrate amphoteric site occupancy: Ho exists solely as Ho3+ at both Ba and Ti sites, while Tb exhibits mixed valence states as Ba-site Tb3+ and Ti-site Tb4+. As the doping content increases, the concentration of Tb4+ at Ti sites decreases, and the quantity of Ba-site Ho3+ ions initially increases to a maximum before decreasing. Defect compensation mechanisms within the samples are also discussed.
Source: Materials
DOI: 10.3390/ma18122914
Authors: Junwei Liu, Xin Wei, Qiaoli Liu, Qiaoli Liu, Yupei Ran, Guoqi Xu, Qi Liu, Qi Liu
Institution: Pingdingshan University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4411452321