Linear and nonlinear ac susceptibilities in polycrystalline low-bandwidth Pr1-xCa(x)MnO3(x = 0.0 − 0.3) manganite

The complex linear and nonlinear ac susceptibility have been thoroughly investigated in the low bandwidth manganite compound Pr(1-x)Ca(x)MnO3 (PCMO) for the doping range x = 0.0-0.3 with and without a superimposed background dc field. The dynamical ac response shows substantial differences between the samples. The sample with x = 0.1 is found to have two separate magnetic transition peaks, compared to the single transitions in the samples x = 0.0 and x = 0.2. The nonlinear ac susceptibility measurements were compared between samples, which confirmed that these transition peaks are similar in nature and from the same magnetic origin. Additionally, for sample x = 0.3 a complex transition peak structure with overlapping transition peaks was found. This kind of evolution of the magnetic phases as a function of the Ca concentration is believed to rise from coexisting antiferromagnetic (AFM) and ferromagnetic (FM) orderings, where the Ca concentration controls the amount of FM clusters in the sample. The spin glass characteristics of these complex phase-separated magnetic regimes showed similarities and contradictions with conventional spin glasses, which indicates that this cluster glass behavior arises from the frustration between competing AFM and FM clusters having different magnetic exchange interaction.