Jahn-Teller contribution to the magneto-optical effect in thin-film ferromagnetic manganites

Strong magnetorefractive effect in epitaxial La2/3Ca1/3MnO3 thin films

“…It is expected then that at temperatures close to the ferromagnetic transition, the optical reflectance of manganites changes significantly with the applied magnetic field and, therefore, the MRE should be relevant. Here, we show that these expectations are confirmed and that the MRE is clearly detected at visible wavelengths around the ferromagnetic transition of epitaxial La 2/3 Ca 1/3 MnO 3 (LCMO) films [8]. As a collateral fact, we show that we can harness the MRE to track simultaneously the magnetic and the transport properties by simply measuring the magneto-optical response.…”

“…It is expected, then, that the method described in this work may be useful to give an additional insight into the nature of some structural and electronic transitions driven by magnetic/electric fields or by temperature [8]. H(kOe) 260 K Fig.…”

Magnetorefractive effect in manganites with a colossal magnetoresistance in the visible spectral region

“…Furthermore, this term has been used for almost all (except for the conventional even and odd magneto optical phenomena) mechanisms of the magnetoreflection and the magnetotransmission, i.e., for all the mechanisms providing the magnetore flection and the magnetotransmission that are not determined by the spin-orbit interaction in the mate rial. For example, the magnetorefractive effect has also been referred to as the contributions introduced into the magnetoreflection and magnetotransmission of the material due to the influence of the magnetic field on the interband optical transitions (the first term in expression (1)) [6], the influence of the magnetic field on the effective mass of polarons in non mag netic insulators without magnetoresistance (the first term in expression (1)) [7], and the suppression of the Jahn-Teller effect by the magnetic field [8]. Although, at first glance, this is not consistent, we will also use the term "magnetorefractive effect" in a broad sense to refer to different mechanisms of magnetoreflection and magnetotransmission, rather than only to a high frequency response to magnetoresistance, every time, whenever possible, specifying the cause of these effects.…”

Cu-doping induced ferromagnetic insulating behavior and domain wall pinning effects in LaMnO3

“…The appearance of Mn 4+ ions in doped manganites, for example, La 1−x Ca x MnO 3 (0.2 < x < 0.4), induces an insulator-metal (I-M) transition with a ferromagnetic (FM) metallic ground state, which has been widely explained by double-exchange (DE) mechanism [4]. Besides, recent studies suggest that phase separation [5] and Jahn-Teller (J-T) distortion [6] are also crucial to explain the capricious physical phase diagrams and CMR effect. Furthermore, the complicated ground states at low temperatures and the multiple interactions in these materials would give more obstacles to the comprehension on the intrinsic physical mechanism.…”