Ultrasonic and elastic moduli evidence for Curie temperature (Tc) in Sm1−xSrxMnO3 perovskite magnetic materials at x=0.25, 0.30, 0.37, 0.40 and 0.44

Effect of rare earth ions on transition temperature in perovskite materials by on-line ultrasonic studies

“…Further, the ionic radii of the R ions are used to know the state of perovskites, that is, PM or AFM states 34 . On the basis of the above studies, it is concluded that a decrease in the T c value, which is obtained from the maxima/minima that are observed in the ultrasonic parameters, strongly supports the results obtained from resistivity, electrical, Mossbauer and magnetic property studies 16,17,19,[22][23][24][25] .…”

“…The composition-and ionic radii-dependent T c values are shown in Figure 1. The observed prominent peaks in U L and U s for all perovskites with different compositions have been obtained from the measured velocities [22][23][24][25] . The T c values obtained from the magnitude of U L and U s in all perovskites and compositions are shown in Figures 2 and 3 respectively.…”

“…The T c values obtained from the magnitude of U L and U s in all perovskites and compositions are shown in Figures 2 and 3 respectively. The maxima/minima values in velocities that are observed are mainly because of the occurrence of lattice softening, that is, the contributed effects of lattice softening above T c and lattice hardening below T c 23,26 . Similarly, the attenuation maxima/minima in all perovskites at the respective T c value that are observed have been identified.…”

On-line phase transition in La1−xSrxMnO3(0.28 ≤ x ≤ 0.36) perovskites through ultrasonic studies

“…The absence of charge-ordering temperature (T co ) in the case of LSMO perovskite manganite materials is already confirmed through studies, such as magnetoresistive measurements [15,41] and electrical measurements [12,19,20]. Therefore, a large magnitude in maximum/minima in ultrasonic velocity and attenuation will be observed [25,42] at T co when compared to T c . Further, to get more information in LSMO perovskite manganite materials, elastic moduli have been obtained over a wide range of temperatures from 298 to 460 K. Elastic moduli are highly sensitive in exploring structural changes in polycrystalline or amorphous materials [41].…”

“…In view of this unique property of ultrasonic waves, ultrasonic measurements [18,25] have been used to explore information about structural changes and associated important physical properties of LSMO perovskite manganite materials. The above-mentioned property of ultrasonic waves helps us to gain knowledge about the origin of metal-insulator transition, structural changes, phase transition and magnetostriction effect on LSMO perovskite manganite materials, which is found to be scanty.…”