Raman spectrum and ESR of Pr0.5Ca0.4Sr0.1MnO3

The powder X-ray diffraction patterns, Raman spectra, magnetization, electron spin resonance (ESR), and resistivity for Pr0.5Ca0.4Sr0.1MnO3 were studied. The Raman spectra change dramatically during the charge ordering transition, and the hardening of the 450 cm−1 mode of the spectra is due to the unit cell reduction of the antiferromagnetic phase. The two resonance signals in the first differentiated lines from ESR spectra suggest the coexistence of ferromagnetic and paramagnetic phases above the charge-ordered temperature, which is also confirmed by the insulator–metallic transition above the charge-ordered temperature induced by magnetic fields.