The magnetic phase diagram of the pseudoternary (${\mathrm{Dy}}_{\mathit{x}}$${\mathrm{Gd}}_{1\mathrm{-}\mathit{x}}$)${\mathrm{Fe}}_{11}$Ti compounds has been experimentally and theoretically investigated. The thermal dependence of the low-field ac susceptibility on powdered samples exhibits a sharp peak, due to an axial-conical spin reorientation (SR) transition. The SR temperature (${\mathit{T}}_{\mathrm{SR}}$) decreases with increasing Gd content. The angular dependence of magnetization on magnetically aligned powdered samples has been measured in a steady applied magnetic field, in the 4.2–300 K temperature range. From these measurements we have determined the angle θ between the spontaneous magnetization and the tetragonal c axis. Onset temperatures for magnetization canting agree with the ${\mathit{T}}_{\mathrm{SR}}$ obtained from susceptibility data within 10 K. Both the ${\mathit{T}}_{\mathrm{SR}}$ vs x and the θ vs T dependences have been calculated using a single-ion, mean-field model for the rare-earth and transition-metal interactions. Very good agreement between theory and experiment was obtained.

• Received 9 May 1994

DOI:https://doi.org/10.1103/PhysRevB.50.12659