MagneticStructures and Excitations of RCrO3 (R = Y and Rare Earth Metals)

This paper investigates the magnetic structures and excitations of the orthochromites RCrO3. The neutron scattering intensities of these magnetic structures were calculated. For scenarios where the R site is non-magnetic, the Bragg peaks I(1 0 1) and I(0 1 1) are good indicators for determining the magnetic structures. On the other hand, when the R3+ sites are ordered magnetic ions, the Bragg peaks I(1 0 0) and I(0 1 0) become the indicators. This paper also discusses the magnetic excitations in RCrO3, with a particular emphasis on the spin Hamiltonian related to the Cr3+ ions. The calculations of spin-wave dispersion considering only exchange interactions indicate that the system lacks stability. Adding single-ion anisotropy stabilizes the system while creating a gap at the Γ point. The addition of the Dzyaloshinskii-Moriya interactions is necessary when the system has weak ferromagnetism, where this interaction not only widens the gap at the Γ point but also creates the gap at the zone boundary, such as [1 0 2].