An optical, EPR and electrical conductivity study of blue barium titanate, BaTiO3−δ

Structure and properties of plasma sprayed BaTiO3 coatings: Spray parameters versus structure and photocatalytic activity

“…The bandgap value reported for thin films range from 3.72 eV to 3.92 eV [21] depending on powder and processing details. The dark blue color of strongly reduced BaTiO 3 (in our case: short SD) is attributed to small-polaron hopping by electrons of Ti 3+ -Ti 4+ charge transfer type and gives evidence of the strongly disordered nature of the material [22]. Our sintered BaTiO 3 sample exhibits a main absorption edge with bandgap energy E bg at 3.68 eV, which corresponds to crystalline structure [5].…”

Abnormal Raman spectra in Er‐doped BaTiO3 ceramics

“…(b)). Discussion about oxygen vacancies (V O ) is neglected because the EPR signal associated with V O is very weak at room temperature …”

Stabilization of small polarons in BaTiO3 by local distortions

“…Indeed, at higher temperature, whether the carrier transport mechanism is small polaron hopping or band conduction is controversial or less discussed than at low temperature, even with single crystals. This would arise from the relatively small temperature dependencies and/or large anisotropy caused by domain structures [13][14][15]46,[49][50][51].…”

“…Small polarons generally play important roles in electronic and ionic transport, optical properties, and charge compensations. In BTO, it has been experimentally reported that small polarons would be the origin of the green luminescence [7][8][9], mid-near-infrared absorption, and blue coloration [10][11][12][13][14]. Especially, the transport of charged carriers has been attributed to hopping of small polarons in some studies [15][16][17][18][19].…”