EPR and optical spectroscopy of neodymium ions in KMgF3 and KZnF3 crystals

Abstract

KMgF 3 and KZnF 3 crystals doped with Nd 3+ ions were studied using EPR and optical spectroscopy methods. Several types of paramagnetic centers of Nd3+: KMgF 3 -two of tetragonal and one of rhombic symmetry, KZnF 3 --one of tetragonal and one of trigonal symmetry were found. Parameters of the corresponding spin Hamiltonians were determined. Using optical spectroscopy paramagnetic centers Nd 2+ and Nd 4+ in KMgF 3 were found.

Electron Paramagnetic Resonance Investigations of Lanthanide-Doped Barium Titanate: Dopant Site Occupancy

“…For Nd 3+ , we could not discern A-site versus B-site by simple EPR arguments, as the same fundamental level is predicted for both dopant sites, and, Ba- and Ti-rich samples have approximately the same amount of Nd 3+ . Despite previous studies suggesting an A-site occupancy, we were not able to identify amphotericity or lack thereof from the present EPR study. Though no Sm 3+ EPR signal was detected, Sm 3+ has been found to be amphoteric in air-fired, very pure BaTiO 3 , consequently supporting the notion that air-firing shifts the “band of amphotericity” to larger ionic radii.…”

“…Consequently, our EPR results on Nd 3+ tell us little about its site substitution. Previously, ionic radii 13 and charge compensation arguments have been used to suggest that Nd 3+ is an A site dopant.…”

Lanthanide series doping effects in lead zirconate titanate (PLnZT) thin films

“…However, the Nd 3+ signal in the PNdZT was similar to that of the Nd 3+ -doped BaTiO 3 system, where the dopant was found to be in a cubic environment and assigned as an A-site cation; 26,27 The Yb 3+ -doped PZT also displays an EPR spectrum that is significantly disordered and does not match spectra expected for either the A or B sites but is similar to a cubic environment. However, the Nd 3+ signal in the PNdZT was similar to that of the Nd 3+ -doped BaTiO 3 system, where the dopant was found to be in a cubic environment and assigned as an A-site cation; 26,27 The Yb 3+ -doped PZT also displays an EPR spectrum that is significantly disordered and does not match spectra expected for either the A or B sites but is similar to a cubic environment.…”

Ab initio, crystal field and experimental spectroscopic studies of pure and Ni2+-doped KZnF3 crystals

“…So far, their properties have been studied mainly with respect to the spectroscopic characteristics of various impurity ions embedded into this host, with the transition metal and rare earth ions being the most frequently used impurities. Thus, the following impurities and phenomena in doped KZnF 3 have been studied: interaction of the Cu 2þ -Mn 2þ pairs [1], spectra of V 2þ [2], Co 2þ and Cr 3þ and laser action of these ions [3,4], the Jahn-Teller effect for Fe 2þ ion [5] and Cr 3þ ions [6], Co 2þ excited state absorption [7] and Co 2þ energy level calculations [8], absorption and emission spectra of Ni 2þ [9], Mn 2þ [10], Cu 2þ [11], Nd 3þ [12], Dy 3þ [13], Yb 3þ [14], Eu 2þ and Ce 3þ ions [15], the pressure induced energy levels crossing for Cr 3þ [16], the Cr 3þ spectra and energy levels [17], interaction of Cr 3þ ions with vacancies [18], ab initio studies of V 2þ [19] and Cr 3þ energy levels using the potential embedded method [20]. The spectra of divalent europium ions in a similar KMgF 3 structure were also reported [21].…”