Magnetic anomalies associated with the Tb3+ level crossing in YBa2Cu3Ox (x ≈ 6.0) in strong magnetic fields up to 50 T

Jumps of the magnetic moment of a Tb:YBa₂Cu₃O _x crystal (x ≈ 6.0) are observed in pulsed magnetic fields of up to 50 T for the field orientations along the [100] and [110] axes. The jumps are caused by the Tb³⁺ level crossing (crossover) in the layered perovskite structure. Based on the previously determined parameters of the crystalline electric field, the Zeeman effect, magnetization curves, and magnetic susceptibility curves are calculated for the Tb:YBa₂Cu₃O _x crystal in the tetragonal phase. The results of calculations provide an adequate description of the magnetic anomalies and the critical parameters of the crossover. The relatively large width of the jumps in magnetization curves can indicate the inhomogeneity of the second-order parameter of the crystalline electric field in the dilute crystals.