Magneto-Electric Spin Resonance of 63Cu2+ Dimer Associates in a BaF2 Single Crystal

Abstract

Unusual resonance lines have been observed for a dimer associate of impurity ⁶³Cu²⁺ ions in a BaF₂ single crystal in continuous-wave electron paramagnetic resonance spectra recorded using a dielectric resonator. The phase of these lines is orthogonal to the phase of magnetic field modulation. The appearance of such lines is attributed to the features of the spin dynamics of high-spin electron systems resonantly interacting with a microwave electromagnetic field. The magnetic dipole moment of the spin system is transformed into the electric quadrupole moment under the sufficiently intense resonant excitation of magnetic dipole transitions. In this case, the interaction of the magnetic dipole and electric quadrupole oscillators occurs in the spin system. The simultaneous excitation of magnetic dipole and electric quadrupole resonant transitions in the dielectric resonator of a spectrometer leads to the appearance of phase-shifted resonance lines.