Eur. Phys. J. B (2012) 85: 180
https://doi.org/10.1140/epjb/e2012-20914-8

Regular Article

Study of Na⁺ ions influence on the charge compensating defects in CaF₂: YbF₃ crystals using dielectric relaxation

¹ Faculty of Physics, West University of Timisoara, 300223 Timisoara, Romania
² Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania

^a e-mail: stef@physics.uvt.ro

Received: 9 November 2011
Received in final form: 27 February 2012
Published online: 4 June 2012

Abstract

YbF₃-doped and NaF co-doped calcium fluoride crystals were grown using the Vertical Bridgman method. Transparent colorless crystals were obtained in graphite crucible in vacuum (≈10^-1 Pa) using a shaped graphite furnace. Room temperature absorption spectra and dielectric spectra were measured to study the effect of Na⁺ ions on the varieties of Yb³⁺ sites in CaF₂ host. The experimental results show that by co-doping with Na⁺ ions in different Na:Yb ratios we can modulate the type of charge compensating defects of Yb³⁺ ions in CaF₂ lattice. Dielectric relaxation in double doped (Yb, Na):CaF₂ crystals-related with the study the charge compensating defects-was not reported before.