Raman spin-lattice relaxation of Pb³⁺in calcite: hyperfine effects

Theory of the Relaxation Processes for Multilevel Spin Systems in Dilute Paramagnetic Solids at High Temperature

“…(3.30a)). In this case, the Lorentzian EPR linewidth at low temperature ÀR ss mn that represents the magnetic dipole±dipole interactions among spins could be negligible [17,18]. Now, w mn and R mn have comparable values, and the linewidths have a strong temperature dependence, so that the spins relax between them and to the lattice with comparable rates so that T 2 T 1 .…”

“…So, the anharmonic effects have been found to be important for the Raman processes of the electron spin±lattice relaxation of paramagnetic defect centres [23]. However, the anharmonicity is expected to have more striking effects on a large amplitude resonance mode [17], or on a relaxaTheory of Relaxation Processes for Multilevel Spin Systems tional soft mode [24] than on the normal modes of the lattice. Consequently by considering in Eqs.…”

Dynamics of CO2−radiation defects in natural calcite studied by ESR, electron spin echo and electron spin relaxation

“…Electron spin-lattice relaxation of paramagnetic ions has been studied in calcite by pulse ESR methods for Fe 3+ [16] and by ESR line width analysis for Pb 3+ [17] showing that the ordinary two-phonon Raman processes govern the relaxation. Two-pulse and four-pulse electron spin echo FT spectroscopy has been used to explain the complexes of Cu 2+ ions on the crystal surface of calcium carbonate mineral vaterite and calcite [18].…”