ESR of Y and Pb-doped BaTiO₃ ceramics with positive temperature coefficient of resistivity

Abstract

Electron spin resonance (ESR) and resistivity investigation of BaTiO₃ ceramics doped by Y and by both Y and Pb are presented. ESR spectra of the Ti³⁺. Mn²⁺ and Fe³⁺ were observed. It is shown that the most intensive resonance line belongs to Ti³⁺-Y³⁺ paramagnetic complex. The essential decrease of the Ti³⁺-Y³⁺ ESR spectra intensity in comparison with those in samples without Pb was revealed. This gives evidence that Pb ions decrease the number of Y³⁺ ions substituted for Ba ions and so the number of Ti³⁺-Y³⁺ centers decreases. Essential shift of the temperature of the PTCR effect beginning and resistivity increasing under Pbdoping are observed.

Key Words:

• ceramics
• ESR
• paramagnetic center
• PTCR effect