Text this: Tunable Magnetic Heating in La<sub>0.51</sub>Sr<sub>0.49</sub>MnO<sub>3</sub> and La<sub>0.51</sub>Dy<sub>0.045</sub>Sr<sub>0.445</sub>MnO<sub>3</sub> Nanoparticles: Frequency- and Amplitude-Dependent Behavior