Electron Magnetic Resonance of Diluted Solid Solutions of Gd³⁺ in BaTiO₃

Electron magnetic resonance (EMR) spectra of gadolinium-doped barium titanate (BaTiO₃) have been studied at room temperature for gadolinium concentrations between 0.20 and 2.00 mol%. The results suggest that the Gd³⁺ ions occupy substitutional sites, replacing the Ba²⁺ ion, that the electron magnetic resonance linewidth increases with increasing gadolinium concentration, and that the range of the exchange interaction between Gd³⁺ ions is about 0.98 nm, of the same order as that of the same ion in other host lattices, such as strontium titanate (SrTiO₃), strontia (SrO), quicklime (CaO), magnesia (MgO) and zircon (ZrSiO4). The fact that the electron magnetic resonance linewidth of the Gd³⁺ ion increases, regularly and predictably, with Gd concentration, shows that the Gd³⁺ ion can be used as a probe to study, rapidly and non-destructively, the crystallinity and degradation of BaTiO₃.

ceramics; electron magnetic resonance; barium titanate; gadolinium