Electron spin resonance on enantiomorphic centers in PbZrO3:Gd3+ crystals

The Gd3+ ESR spectrum of the antiferroelectric phase of a PbZrO3 single crystal contains at least one pair of magnetically equivalent components. The angular dependences of the resonance magnetic field that were constructed for them transform into one another by mirror reflection in a plane perpendicular to the antipolarization axis of the crystal. The constants in the spin Hamiltonians for the corresponding pair of paramagnetic centers are determined assuming monoclinic symmetry.