Temperature-dependent Brillouin scattering studies of surface acoustic modes in Nd0.5Sr0.5MnO3

✍ Scribed by Md.Motin Seikh; Chandrabhas Narayana; Sachin Parashar; A.K. Sood

• Book ID: 104166211
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 225 KB
• Volume: 127
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/s0038-1098(03)00420-4

✦ Synopsis

Brillouin scattering experiments are carried out to study the surface acoustic waves in Nd 0.5 Sr 0.5 MnO 3 as a function of temperature in the range of 40-300 K covering the metal-insulator and charge-ordering phase transitions. The surface modes include surface Rayleigh wave, pseudo-surface acoustic wave (PSAW) and high velocity PSAW. The observed softening of the sound velocities for the surface modes below paramagnetic to ferromagnetic transition, T c is related to the softening of the C 44 elastic constant. The subsequent hardening of the sound velocity below the charge ordering transition temperature T co is attributed to the coupling of the acoustic phonon to the charge ordered state via long range ordering of the strong Jahn -Teller (JT) distortion.