Extended Data Fig. 2: Temperature dependence of the absorbance of TbInO3 in the near-infrared and visible region.
From: Unconventional room-temperature carriers in the triangular-lattice Mott insulator TbInO3
The absorbance of a 500 μm-thick TbInO3 crystal for temperatures from 295 K down to 4 K. This experiment was conducted in an optical cryostat (Cryostation, Montana Instruments, USA) by using a grating spectrometer (Cary 5000, Agilent, USA). The low energy excitations under 1 eV are transitions to spin-orbit split multiplets, 7F2 and 7F0 in that order, and this result is well matched with the previous report of Raman spectroscopy30. In the high energy side, a strong absorption edge was detected above 2 eV in the entire temperature range. We proposed that the large absorption edge is the Mott charge gap of TbInO3. This optical gap exhibits blueshift by cooling from 2.257 eV to 2.362 eV.
