Optical Evidence of Multiphase Coexistence in Single Crystalline (La,Pr,Ca)MnO3

TL;DR

This study uses optical spectroscopy to reveal the coexistence of multiple phases, including charge-ordered, ferromagnetic metallic, and charge-disordered phases, in a single crystal of La,Pr,Ca manganite at low temperatures.

Contribution

It provides direct optical evidence of multiphase coexistence in La,Pr,Ca manganite, highlighting the presence of distinct electronic phases at low temperatures.

Findings

Charge-ordered phase dominates between T_C and T_CO with a ~0.4 eV gap.

Emergence of ferromagnetic metallic and charge-disordered phases below T_C.

Multiphase coexistence suggests different lattice strains in the material.

Abstract

We investigated temperature (T)- and magnetic field-dependent optical conductivity spectra (\s\w) of a La_5/8-yPr_yCa_3/8MnO_3 (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 < T_C, at least two absorption bands newly emerge below 0.4 eV. Analyses of (\s\w) indicate that the new bands should be attributed to a ferromagnetic metallic and a charge-disordered phase that coexist with the charge-ordered phase. This optical study clearly shows that La_5/8-yPrCa_3/8MnO_3 (y~0.35) is composed of multiphases that might have different lattice strains.