Journal Article

FZJ-2015-04188

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Peculiar size effect in nanocrystalline BaTiO$_{3}$

Guo, X. (Corresponding Author)FZJ*

2013
Elsevier Science Amsterdam [u.a.]

This record in other databases:  

Please use a persistent id in citations: doi:10.1016/j.actamat.2012.11.049

Abstract: Dense BaTiO3 ceramics with grain sizes of 35 nm to 5.6 μm were prepared, and the electrical properties investigated in the temperature range 500–700 °C by means of impedance spectroscopy. Charge carriers (oxygen vacancies and holes) are depleted in the space charge regions at the BaTiO3 grain boundaries. When the grain size is ⩾250 nm, the width of the space charge region was determined to be ∼40 nm. Therefore, the depletion regions were expected to overlap when the grain size decreases to 35 nm; in such a situation, charge carriers would be depleted over the entire grain, resulting in depressed conductivity. However, the conductivity of the 35 nm grain size sample was measured to be one to two orders of magnitude higher than those of the microcrystalline samples, and the activation energy markedly lower. Moreover, we determined a width of ∼7 nm for the space charge regions in the 35 nm grain size sample; therefore, the space charge regions do not overlap. The enhanced conductivity is ascribed to a reduced oxidation enthalpy in nanocrystalline BaTiO3, and the distorted grain boundaries in nanocrystalline BaTiO3 are believed to be the atomic level origin of the reduced oxidation enthalpy.

---

Contributing Institute(s):

1. Elektronische Materialien (PGI-7)

Research Program(s):

1. 424 - Exploratory materials and phenomena (POF2-424) (POF2-424)

---

Database coverage:
; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---