Superhyperfine Structure of the EPR Spectra of Nd³⁺Impurity Ions in Fluorite CaF<inf>2</inf>

© 2018, Pleiades Publishing, Ltd. EPR spectra of a CaF2single crystal that was grown from melt containing a small addition of NdF3were studied. Signals corresponding to tetragonal centers of Nd3+ions and cubic centers of Er3+ and Yb3+ ions were found. Superhyperfine structure (SHFS) in the spectra of the Nd3+ions was observed for the first time in this crystal; parameters of the superhyperfine interaction of the Nd3+ions with the nearest nine fluorine ions were determined. The dependence of the resolution of the Nd3+EPR spectrum SHFS on the incident microwave power at the temperature of T ≈ 6 K was studied. Obtained results are discussed and compared with the literature data