Order parameters in lanthanum gallate lightly doped with manganese and paramagnetic resonance

The Cr$^{3+}$ centers have been revealed, transitions at room temperature have been identified, and spin Hamiltonian parameters have been determined for the Cr$^{3+}$ and Fe$^{3+}$ triclinic centers in lanthanum gallate lightly doped with manganese. The principal axes of the fourth-rank fine-structure tensor for the Fe$^{3+}$ triclinic centers have been established and used to determine the order parameters, i.e., the angles of rotation of oxygen octahedra of lanthanum gallate with respect to the perovskite structure. The order parameter in the rhombohedral phase has been estimated.