Structural and phase transition of Mg-doped on Mn-site in La0.7Sr0.3MnO3 bulk/nanostructured perovskite characterised through online ultrasonic technique

Bulk and nanoshaped perovskite manganite materials were blended to form samples of La0.7Sr0.3Mg1−xMnxO3 (LSMMO) with x = 0.05, 0.075, and 0.100 employing solid state and sonochemical methods, respectively. The well-formed LSMMO component was characterized by comprehensive characterization techniques and rhombohedral structure was observed. The mean size of the bulk and nano LSMMO manganite perovskites ranges between 260-850 nm and 23-86 nm, respectively. The structural and phase transition of the manganite perovskites are explored by on-line ultrasonic velocity and attenuation measurements between 300 and 400 K. A deliberate change in the ultrasonic velocity, attenuation and elastic moduli shows an abnormal behavior with temperature in perovskites and was associated with the occurrence of ferromagnetic-paramagnetic (FM-PM) transition temperature (TC). In addition, the shifts in TC magnitude and width by increase in x are used to study the etiquette of TC and the change in the nanostructure of the bulk perovskites.