Magnetism: Magnetic ions in insulators, their interactions, resonances, and optical properties

anisotropy energy antiferromagnetic antiferromagnetic resonance antiparallel assumed atoms axes axis calculation cm-¹ Co² coefficients components constant covalency crystal field crystalline field cubic Curie temperature direction discussed effect electrons equations exchange energy exchange integral exchange interaction excited experimental expression external field Fe2+ Fe3+ ferrites field theory given by Eq Hamiltonian Hartree-Fock induced anisotropy iron garnet K₁ lattice ligand field ligand field theory linear M₁ M₂ magnetic dipolar interaction magnetic field magnetic ions magnetic moment magnetostriction matrix elements molecular field approximation Moriya nearest-neighbor Néel Néel temperature neighbors observed obtained optical orientation orthogonal P. W. Anderson pairs parallel paramagnetic parameters phenomenological Phys plane polarization problem pseudodipolar result S₁ S₂ Section spin arrangement spin Hamiltonian spin wave spin-orbit coupling splitting sublattice magnetizations superexchange susceptibility symmetry temperature dependence theoretical tion torque transition trigonal values vector Vleck wave function weak ferromagnetism ytterbium zero