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

Abstract

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.