Charge-Ordering Breakdown Dynamics and Ferromagnetic Resonance Studies of B-site Cu Diluted Pr1‒xSrxMnO₃

Here, we report the influence of Jahn–Teller active Cu substitution on the charge-ordering (CO) characteristics of one of the well-known manganite Pr 0.45 Sr 0.55 MnO 3 (S55) with a distorted tetragonal structure. Magnetization studies unveil a complex magnetic phase diagram for S55, showing distinct temperature ranges corresponding to various magnetic phases: a ferromagnetic phase dominated by the Double Exchange interaction with T C ∼ 220.5 K, an antiferromagnetic phase below T N ∼ 207.6 K induced by CO with a transition temperature of T CO ∼ 210 K consistent with the specific heat C P (T) data, and a mixed phase in the range T N < T < T CO due to the competitive interplay of these two interactions. Dilute substitution of Cu at the Mn B -sites disrupts the robust charge-ordered state, leading to enhanced ferrimagnetic order with T FN ∼273 K and significant magnetocrystalline anisotropy as confirmed by ferromagnetic resonance (FMR) studies. The Cu-substituted system displays a distinct cationic distribution compared to the pristine S55, contributing to its diverse magnetic structure. Our findings also reveal the irreversible metamagnetic transition ( H T-Max ∼ 8.85 kOe at 180 K) associated with the CO phenomena in S55 and the first-order nature of the phase transition across T CO . The magnetic heat capacity critical analysis ( C Mag = A ( T − T N ) − α ) yields the exponent, α = 0.097 (0.154) in the region T > T N ( T < T N ) consistent with the magnetic structure. The temperature dependence of FMR resonance field Δ H Res ( T ), peak-to-peak width H PP ( T ), and Gilbert damping factor α G ( T ) show clear anomalies across the magnetic transitions signifying the important role of admixtured (3+/4+) electronic state of Mn. Additionally, a strong correlation between the FMR α G (T) and switchable magnetic entropy change ( ΔS Max ∼ −8/+ 3 J kg −1 K −1 for ΔH = 90 kOe) has also been established in S55.