Low-temperature high-pressure spectroscopy of lanthanum lutetium gallium garnet crystals doped withCr3+andNd

Theoretical study of pressure shift for R line of Cr3+ ion in lanthanum lutetium gallium garnet

“…The crystal field experienced by dopant ions in lanthanum lutetium gallium garnet (LLGG : La 3 Lu 2 Ga 3 O 12 ) crystals is lower than in other garnets [1][2][3][4][5]. It is especially interesting for Cr 3+ ions, since the low strength of the crystal field profoundly affects the luminescence properties of this dopant [1,2] where B and C are Racah parameters and Dq the cubic crystal-field parameter.…”

“…It is especially interesting for Cr 3+ ions, since the low strength of the crystal field profoundly affects the luminescence properties of this dopant [1,2] where B and C are Racah parameters and Dq the cubic crystal-field parameter. Obviously, the increase of the strength of the crystal field, due to the increase of the pressure, reflected by the increase of the Dq parameter, should lead to an increase of the energy of the Recently, a series of theoretical studies [9,10] based on a molecular-orbital model deals well with the optical and magnetic experiments for Fe 2+ (3d…”

“…hϖ [2] is the phonon energy, and α and β refer to the vibration levels in 2 E and 4 T 2 energy potentials [2], respectively. The present theoretical results are in qualitative agreement with experiments, which is a progressing as compared with the crystal-field approximation.…”

“…Usually, the transitions from the obtained first and second 2 E levels to the ground state 4 A 2 are named R 1 and R 2 , respectively. Taking the spin-orbit parameter ζ = 350 cm -1 [2] for Cr 3+ ions and p ζ = 154 cm -1 [22] for ligands O in LLGG, the values of R 1 = 14530 and the difference ∆ = 34 cm -1 between R 1 and R 2 obtained by diagonalization of Eq. (1) are in good agreement with experimental observations [2].…”

“…Taking the spin-orbit parameter ζ = 350 cm -1 [2] for Cr 3+ ions and p ζ = 154 cm -1 [22] for ligands O in LLGG, the values of R 1 = 14530 and the difference ∆ = 34 cm -1 between R 1 and R 2 obtained by diagonalization of Eq. (1) are in good agreement with experimental observations [2]. This agreement thus provides a further check of the present values of the crystal-field parameters B, C and Dq as well as λ .…”