First-principles study of the electronic structure of Pb(ZrTiNb)O3 (PZTN) systems

Autor:	Tamio Oguchi, Takeshi Kijima, Tatsuya Shimoda, Hiromu Miyazawa, Taku Aoyama, Takamitsu Higuchi, Eiji Natori
Rok vydání:	2003
Předmět:	Materials science Condensed matter physics Atomic orbital Transition metal Band gap Bandgap narrowing Atom Electronic structure Madelung potential Thin film
Zdroj:	MRS Proceedings. 784
ISSN:	1946-4274 0272-9172
DOI:	10.1557/proc-784-c3.12
Popis:	Using first principles calculations, we have investigated the electronic structure of Pb(ZrTiNb)O3 (PZTN), a system with a low leakage current and high reliability in thin films. We proposed that in PZTN, the oxygen vacancy is suppressed due to the addition of a Nb atom at the B site and that this change prevents a bandgap narrowing which would enhance the leakage current. The oxygen vacancy in the perovskite structure reduces the bandgap because it lowers the d orbital energy of the nearest-neighbor transition metal through the Madelung potential; this bandgap narrowing induces the leakage current in conventional Pb(ZrTi)O3 (PZT) systems with the Shottky type Pb-O deficit. In contrast, the PZTN systems, which also have the Pb deficit but lack the oxygen vacancy, can maintain the bandgap, and attain a low leakage current.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7fe861127b651487a46c15b431aa1479 https://doi.org/10.1557/proc-784-c3.12 Zobrazit plný text záznamu Full text from SpringerLink