Magnetic Properties of La₃Ga_5.5Ta_0.5O₁₄ Single Crystals Doped with Sm³⁺ and Er³⁺ Ions

Abstract

Electron paramagnetic resonance and magnetic susceptibility measurements were performed for two La3Ga5.5Ta0.5O14 single crystals doped with 1.96 at.% of Sm 3+ ions and 3.8 at.% of Er 3+ ions. Two magnetically inequivalent sites were found to be responsible for the electron paramagnetic resonance spectra of Sm 3+ ions. Both sites reveal a low (at least C2) symmetry with gx ∼ 0.46, gy ∼ 0.46 and gz ∼ 0.52. The symmetry of isolated erbium ions is higher than C2. From electron paramagnetic resonance and magnetic susceptibility experiments it results that the ground state of Er 3+ ions is Γ 6 or Γ 7 . Below 51 K electronic transitions within Γ 6 doublets take place. Between 51 and 60 K, Γ 6 to Γ 7 transitions dominate, while above 60 K mainly transitions within Γ 7 doublet are active.

Electron Paramagnetic Resonance: A Technique to Locate the Nearest Environment of Chromium Luminescent Centers

“…Luminescent ions are those whose energy levels allow them to emit radiation in the infrared, visible light, and ultraviolet ranges. These ions include rare earth (RE) ions (e.g., Ce 3+ , Nd 3+ , Eu 3+ , Eu 2+ , Dy 3+ , Er 3+ , Yb 3+ ) − and transition metal ions (e.g., Mn 2+/3+/4+ , Cr 3+ , Ni 2+ ). − Due to the high cost of RE ions, transition metal ions are increasingly used. Transition metal ions most often occupy octahedral or tetrahedral sites depending on the valency of these ions.…”