By Topic

Semiconductor-to-insulator transition of undoped-BaTiO3 in quenched state

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

The purchase and pricing options are temporarily unavailable. Please try again later.
4 Author(s)
Kwon, Hyung-Soon ; Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Republic of Korea ; Yoo, Han-Ill ; Kim, Chang-Hoon ; Hur, Kang-Heon

Your organization might have access to this article on the publisher's site. To check, click on this link: 

It has been believed that the defect structure of “undoped” BaTi1-ηO3-δ be governed by background acceptor impurities, most likely AlTi, in its near stoichiometry regime (δ≈0). Its electrical conductivity versus oxygen activity should, thus, be expected to be similar to that of Al-doped BaTiO3 not only in equilibrium state at elevated temperatures, but also in quenched state at low temperatures. In quenched state, however, the “undoped” BaTiO3 from various sources totally betray this expectation: A landmark of the quenched-state defect structure, semiconductor-to-insulator transition falls at an oxygen activity >10 orders lower than that of the Al-doped and it is rather similar to that of variable-valent Mn-doped BaTiO3. The transition is found to systematically depend on the nonmolecularity (η), suggesting the defect structure being governed by the multiply-charged cation vacancies. The hole-trapping energies of VBa and VTi are estimated and compared with those for the fixed-valent AlTi and variable-valent MnTi.

Published in:

Journal of Applied Physics  (Volume:107 ,  Issue: 8 )