Optical evidence of multiphase coexistence in single crystalline (La, Pr, Ca)MnO₃

We investigated temperature (T)- and magnetic field-dependent optical conductivity spectra σ(ω) of a La_5/8-yPr_yCa_3/8MnO₃(y≈0.35) single crystal, showing intriguing phase coexistence at low T. At T_c<T <T_CO, a dominant charge-ordered phase produces a large optical gap energy of ∼0.4 eV. At T<Tc, at least two absorption bands newly emerge below 0.4 eV. Analyses of σ(ω) indicate that the bands should be attributed to a ferromagnetic metallic phase and a charge-disordered phase that coexist with the charge-ordered phase. This optical study clearly shows that La_5/8-yPr_yCa_3/8MnO₃(Y≈0.35) is composed of multiphases that might have different lattice strains.