Details

Autor(en) / Beteiligte

• Siebenhofer, Matthäus
• Baiutti, Federico
• de Dios Sirvent, Juan
• Huber, Tobias M.
• Viernstein, Alexander
• Smetaczek, Stefan
• Herzig, Christopher
• Liedke, Maciej Oskar
• Butterling, Maik
• Wagner, Andreas
• Hirschmann, Eric
• Limbeck, Andreas
• Tarancon, Albert
• Fleig, Jürgen
• Kubicek, Markus

Titel

Exploring point defects and trap states in undoped SrTiO3 single crystals

Ist Teil von

• Journal of the European Ceramic Society, 2022-04, Vol.42 (4), p.1510-1521

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The defect chemistry and electronic trapping energies in undoped single crystalline SrTiO3 were examined by electrochemical impedance spectroscopy at low (25–160 °C) and intermediate (500–700 °C) temperatures. Electronic and ionic conductivity as well as chemical capacitance values were obtained with a transmission line equivalent circuit. Impedance spectroscopy at low temperatures was used to quantify trapping energies of main ionic defects. Particularly the chemical capacitance is shown to be a highly valuable, though hardly used tool for establishing a defect model based solely on electrochemical measurements. It is very sensitive for minority charge carriers and can thus unveil otherwise hardly accessible defect concentrations. The chemical capacitance analysis yields a valence dependent acceptor concentration in the ppm range for the investigated samples. Complementary positron annihilation lifetime spectroscopy (PALS) suggests existence of Ti vacancies and both methods (chemical capacitance and PALS) agree in their quantification of the corresponding vacancy concentration (6 ppm). Beyond successfully predicting acceptor defect concentrations in undoped SrTiO3, the method is sensitive for electronically relevant defects in sub-ppm concentrations.