Anisotropic optical spectra in a detwinned LaMnO3 crystal -: art. no. 184421

We have investigated anisotropic optical conductivity spectra over a wide temperature range, 10 K less than or equal to T less than or equal to 800 K, for a detwinned single crystal of LaMnO3, which undergoes the orbital ordering at T-OO approximate to 780 K and the A-type antiferromagnetic ordering at T-N approximate to 140 K. The charge-gap transition peaking around 2 eV shows a clear anisotropy for the polarizations parallel and perpendicular to the c axis (Pbnm setting). With the increase of temperature, the anisotropy and the gap magnitude are gradually suppressed toward T-OO, while least affected by spin disordering at T-N. indicating the strong charge-transfer character of gap transition.