Crystal growth, structure and crystal field splitting and fitting of Yb:GdScO₃

Abstract A good quality (5 at.% Yb:GdScO 3 ) single crystal of Φ 30 mm × 37 mm was grown successfully by the Czochralski method. Its structure is studied by the x-ray diffraction (XRD), and its atomic coordinates are obtained by Rietveld refinement. The crystal field energy level splitting of Yb 3+ in GdScO 3 is determined by employing the absorption and photoluminescence spectra at 8 K. Only 2 F 7/2 (4) is far from the ground state 2 F 7/2 (1) by 710 cm −1 among the crystal field energy levels split from 2 F 7/2 , so it is more easier to realize the laser operation of 2 F 5/2 (1)→ 2 F 7/2 (4) with wavelength 1060 nm. The spin–orbit coupling parameters and intrinsic crystal field parameters (CFPs). The intrinsic crystal field parameters <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mover accent="true"> <mml:mi>B</mml:mi> <mml:mo stretchy="false">¯</mml:mo> </mml:mover> <mml:mi>k</mml:mi> </mml:msub> </mml:mrow> </mml:math> ( k = 2, 4, 6) of the crystal were fitted by the superposition model. The CFPs evaluated with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mover accent="true"> <mml:mi>B</mml:mi> <mml:mo stretchy="false">¯</mml:mo> </mml:mover> <mml:mi>k</mml:mi> </mml:msub> </mml:mrow> </mml:math> and coordination factor are taken as the initial parameters to fit the crystal field energy levels of the crystal, and the crystal field parameters <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>q</mml:mi> <mml:mi>k</mml:mi> </mml:msubsup> </mml:mrow> </mml:math> are obtained finally with the root-mean-square deviation 9 cm −1 . It is suggested that the ligand point charge, covalency and overlap interaction are slightly weaker than charge interpenetration and coulomb exchange interaction for Yb 3+ in GdScO 3 . The obtained Hamiltonian parameters can be used to calculate crystal field energy levels and wave functions of Yb:GdScO 3 to analyze the mechanism of the luminescence or laser.