Charge-ordering breakdown dynamics and ferromagnetic resonance studies ofB-site Cu diluted Pr1‒xSrxMnO3.

ABSTRACT

Here, we report the influence of Jahn-Teller active Cu substitution on the charge-ordering (CO) characteristics of one of the well-known manganite Pr0.45Sr0.55MnO3(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 withTC∼ 220.5 K, an antiferromagnetic phase belowTN∼ 207.6 K induced by CO with a transition temperature ofTCO∼ 210 K consistent with the specific heatCP(T) data, and a mixed phase in the rangeTNcharge-ordered state, leading to enhanced ferrimagnetic order withTFN∼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 (HT-Max∼ 8.85 kOe at 180 K) associated with the CO phenomena in S55 and the first-order nature of the phase transition acrossTCO. The magnetic heat capacity critical analysis (CMag=A(T-TN)-α) yields the exponent,α=0.097 (0.154) in the regionT>TN(Tmagnetic structure. The temperature dependence of FMR resonance field ΔHRes(T), peak-to-peak widthHPP(T), and Gilbert damping factorαG(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 FMRαG(T) and switchable magnetic entropy change (ΔSMax∼-8/+ 3 J kg-1K-1forΔH=90 kOe) has also been established in S55.