Online Ultrasonic charecterisation of bulk and nano perovskites and maraging steel

Abstract

Over the past few years the development and improvement of advance newlinematerials like RAMO where R trivalent rare earth elements and A divalent newlinealkaline earth ions perovskite manganites were required for potential applications newlinelike solid oxide fuel cells magnetic sensorsreading heads and frequency switching newlinedevices The development of nanostructured perovskite manganite material has newlinebeen explored in the fields of information technology telecommunication and newlinemedicine In the present study the three series of bulk and nanocrystalline newlineLCMO LCMO 075 080 and 085 LPMO LPMO newline03 04 and 05 and LSMO LSMO 032 035 and 037 perovskite newlinemanganite particles are prepared employing respectively solid state and newlinesonochemical reaction methods newlineThe complete characterisation of prepared samples is made by studies newlinesuch as density Xray diffraction XRD Energy dispersive analysis of an Xray newlinespectrometer EDX Fourier transform of infrared spectroscopy FTIR Scanning newlineelectron microscope SEM Transmission electron microscope TEM and surface newlinearea measurement S An indigenously designed experimental setup is used for newlineonline measurement of ultrasonic velocities and attenuation over wide range of newlinetemperatures from 300 to 400 K The temperature dependent ultrasonic parameters newlineshow an interesting anomaly in both bulk and nano perovskite samples The newlinemarked softening and hardening in sound velocities and attenuation are related to newlinephase transition temperature newlineThe existence of the crystalline nature with the orthorhombic crystal newlinestructure of bulk and nano LCMO perovskite samples is revealed through the XRD newlinepattern In addition the value of diffraction angle 2 is shifted to a lower value in newlinenano LCMO perovskite manganite when compared with the corresponding newlinecomposition of bulk LCMO samples The SEM TEM and BET characterisation newlinestudies confirms the particle size of bulk LCMO perovskite samples as 075 85 m newlineand for nano LCMO perovskite samples as 120 160 nm newline newline