Aging-Resistant Behavior and Room Temperature Electron Spin Resonance of Nd3+ in Singly and Doubly Doped BaTiO3 Ceramics Associated with Preservation History

Abstract

The (Ba0.96Nd0.04)Ti0.99O3 (BN4T) and (Ba0.96Nd0.04)(Ti0.94Ce0.05)O3 (BN4TC5) ceramics were prepared via the mixed oxide route exhibited tetragonal and pseudo-cubic structures, respectively. After they were preserved over a long period of time, a broader electron spin resonance (ESR) signal at g = 2.338 and a narrow ESR signal at g = 2.151 were detected at room temperature (RT) for BN4T and BN4TC5, respectively. They most likely originated from the Nd3+ Kramers ions in BN4T and Nd3+-Ce4+ defect complexes in BN4TC5 ceramics, respectively. The origins of these two ESR signals and the aging-resistant dielectric behavior are further discussed.

Electron Paramagnetic Resonance Study on Oxygen Vacancies and Site Occupations in Mg-Doped BaTiO3 Ceramics

“…Many transition metal ions with lower valence states occupy the B site when doped in BaTiO 3 , for example, Mn 2+ [7,8]. Similar to these dopants, Mg 2+ was also considered to be substituted for the B site as an acceptor because 6-CN Mg 2+ is closer to Ti 4+ in ionic size, and the defect notation was written as MgTi′′ according to the defect notation proposed by Kröger and Vink [9]. Considering the electroneutrality, MgTi′′ was usually compensated by one oxygen vacancy (VO••) and MgTi′′−VO•• pairs were supposed to exist in BaTiO 3 [10,11,12,13].…”