Divalent Impurity Ions in Potassium Tantalate Studied by EPR

Abstract

EPR results of potassium tantalate single crystals doped by Co²⁺ ions as well as new results of our continuous studies of KTaO₃: Cu single crystal have been submitted. Divalent impurity ions substitute for Ta⁵⁺ in the octahedron position in the KTO₃ crystal and oxygen vacancies are required to compensate the extra charge of Ta⁵⁺. The Cu²⁺ ions associated with oxygen vacancies form only axial centres (included exchange coupled pair centre), the symmetry axes being along cubic directions. New axial centre of Co²⁺ in the crystal of KTaO₃: Co have been studied.

Keywords:

• EPR
• potassium tantalite
• divalent impurities

Acknowledgments

This work was supported by grant LN00A015 of the MSMT CR and RFBR grant 03-02-17632. Badalyan A. would like to thank the Russian Academy of Sciences for support in the frame of the program “Spin depended effects in solids and Spintronic”.