Anomalies of ultrasonic velocities, attenuation and elastic moduli in Nd 1− x Sr x MnO 3 perovskite manganite materials

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.…”

“…Ultrasonic velocities were measured using a high-power ultrasonic process control system (FUI1050; Fallon Ultrasonics Inc., Canada), a 100 MHz DSO (54600B; HP, USA) and a PC as discussed in our earlier studies 22 .…”

“…The attenuation coefficient was calculated by measuring the amplitude of received pulses with waveguides (A w (f)) and waveguides with sample (A s (f)), using the following relation 22 :…”

Synthesis and on-line ultrasonic characterisation of bulk and nanocrystalline La0.68Sr0.32MnO3 perovskite manganite

“…The on-line ultrasonic velocity, attenuation and the derived acoustical parameters are widely used to explore phase transitions like Neel temperature (T N ), Curie temperature (T C ), charge ordering temperature (T CO ), etc., in the temperature region between 77 and 270 K in perovskite magnetic materials [26], Nd 1−x Sr x MnO 3 (x = 0.31, 0.35, 0.37, 0.39 and 0.41) [27], La 1−x Ca x MnO 3 (x = 0.19 and 0.82) [28] and La 0.67 Ca 0.33−x Sr x MnO 3 (x = 0, 0.09, 0.13, 0.33) [29]. These studies revealed that on-line ultrasonic characterisation is a versatile tool used to explore the phase and structural transitions in solid materials particularly perovskite maganities [30].…”