SrBi2Ta2O9 has only two polar axes - a problem for high density ferroelectric memory devices

Citation
K. Franke et al., SrBi2Ta2O9 has only two polar axes - a problem for high density ferroelectric memory devices, SOL ST COMM, 119(3), 2001, pp. 117-119
Citations number
15
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
SOLID STATE COMMUNICATIONS
ISSN journal
00381098 → ACNP
Volume
119
Issue
3
Year of publication
2001
Pages
117 - 119
Database
ISI
SICI code
0038-1098(2001)119:3<117:SHOTPA>2.0.ZU;2-X
Abstract
In the microscopic polarization-switching of SrBi2Ta2O9 (SBT) thin films, a significant proportion of the crystallites have proved to remain unswitcha ble. From the Curie-rule and from hysteresis measurements of SET material w ith uniform crystal orientation, it follows that SET posseses only two pola r axes. The switchable polarization of polycrystalline films with different numbers of polar axes is simulated numerically. It is shown that SET capac itors with large-size electrodes may exhibit good switchability. However fo r high density memory applications, severe microstructural orientation requ irements must be fulfilled to avoid switching failures. Materials with more than two polar axes make far reduced or no demands regarding texture quali ty. (C) 2001 Elsevier Science Ltd. All rights reserved.