The low temperature phenomenology of Strontium Titanate is rich and intriguing, with anomalies producing signals of small intensity. We show that depolarization pyrocurrents are a suitable technique to greatly enhance these features, otherwise rather elusive when observed with other methods. Depolarization currents have been measured on a single phase sintered SrTiO3 pellet, prepared by solid state reaction. They increase with increasing poling voltage and switch to symmetric negative values by inversion of the poling sign, which is a property commonly considered as a clue of ferroelectricity. Moreover, three intensity maxima are revealed at T=16, 24 and 45 K respectively. In particular, the anomaly at T45 K can be associated with the emerging of ferroelectricity in walls between antiphase ferroelastic domain walls, whose nanoscale polar character is already known from literature.We demonstrate and estimate such ferroelectricity reconstructing a static polarization hysteresis loop by applying suitable poling patterns.
Low temperature ferroelectricity in Strontium Titanate domain walls detected by depolarization pyrocurrents
Cabassi R;Trevisi G;
2021
Abstract
The low temperature phenomenology of Strontium Titanate is rich and intriguing, with anomalies producing signals of small intensity. We show that depolarization pyrocurrents are a suitable technique to greatly enhance these features, otherwise rather elusive when observed with other methods. Depolarization currents have been measured on a single phase sintered SrTiO3 pellet, prepared by solid state reaction. They increase with increasing poling voltage and switch to symmetric negative values by inversion of the poling sign, which is a property commonly considered as a clue of ferroelectricity. Moreover, three intensity maxima are revealed at T=16, 24 and 45 K respectively. In particular, the anomaly at T45 K can be associated with the emerging of ferroelectricity in walls between antiphase ferroelastic domain walls, whose nanoscale polar character is already known from literature.We demonstrate and estimate such ferroelectricity reconstructing a static polarization hysteresis loop by applying suitable poling patterns.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.