Effects of magnetic field, anisotropy, and biquadratic interactions in type-IIA fcc antiferromagnets studied by linear spin-wave theory

We study the spin dynamics in a 3D quantum antiferromagnet on a face-centered-cubic (fcc) lattice. The effects of magnetic field, single-ion anisotropy, and biquadratic interactions are investigated using linear spin-wave theory with spins in a canted basis about the type-IIA fcc antiferromagnetic ground state structure which is known to be stable. We calculate the expected finite-frequency neutron scattering intensity and give qualitative criteria for typical fcc materials MnO and CoO. The magnetization reduction due to quantum zero point fluctuations is also analyzed.