Nanoscale phase separation in La_0.7Ca_0.3MnO₃films: evidence for texture-driven optical anisotropy

Abstract

The IR optical absorption (0.1-1.5 eV) in the $La_{0.7}Ca_{0.3}MnO_3$ films\non LAO substrate exhibits the drastic temperature evolution of the spectral\nweight evidencing the insulator to metal transition. Single crystal films were\nfound to reveal strong linear dichroism with anomalous spectral oscillations\nand fairly weak temperature dependence. Starting from the concept of phase\nseparation, we develop the effective medium model to account for these effects.\nThe optical anisotropy of the films is attributed to the texturization of the\nellipsoidal inclusions of the quasimetal phase caused by a mismatch of the film\nand substrate and the twin texture of the latter.\n