On-line phase transitions of bulk and nanocrystalline La1−xPbxMnO3 (x=0.3, 0.4, and 0.5) perovskite manganite materials using ultrasonic measurements

摘要: Abstract Bulk and nanostructured La1−xPbxMnO3 perovskite manganite samples for different Pb contents (x = 0.30, 0.40 0.50) were synthesised using solid-state reaction sonochemical methods, respectively. XRD, FTIR, SEM, EDAX, BET TEM studies carried out to characterise the prepared bulk nanosamples. The XRD characterization confirmed that nano crystalline in nature. SEM revealed particle sizes of is range 0.75–85 μm, whereas it ranges from 50 90 nm case samples. Further, has been there an increase size with content both In addition, ultrasonic velocities attenuations nanosamples measured on-line through transmission method. temperature-dependent parameters showed interesting anomaly observed marked softening hardening sound attenuation related ferromagnetic paramagnetic phase transition temperature (TC). perovskites samples, existence diffused took place at a lower compared corresponding broad (FM)–paramagnetic (PM) confirms absence sharp transition, which attributed coexistence orbitally, ordered disordered phases. spin–phonon electron–phonon couplings are known exist because single ion magnetostriction dynamic Jahn–Teller effect, respectively, evidenced by anomalies attenuations.