EPR Spectroscopy of Impurity Ytterbium Ions in Synthetic Forsterite Single Crystals

Continuous wave and pulse X-band electron paramagnetic resonance spectroscopy are used to determine structure, magnetic and relaxation properties of paramagnetic centers formed by impurity ytterbium ions in forsterite (Mg2SiO4) single crystals. It is found that Yb3+ ions substitute Mg2+ ions both as single ions and as dimeric associates with nearby magnesium vacancy. For all ytterbium centers, magnetic properties are characterized by the strong easy plane anisotropy. Measurements in temperature range 5–15 K showed that spin–lattice relaxation of the Yb3+ ions in Mg2SiO4 is due to joint action of direct one-phonon process, Raman two-phonon process and resonance two-phonon Aminov–Orbach process.