کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9586230 | 1505939 | 2005 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Photogeneration of charged ferroelectric domains in quantum dielectric SrTiO3
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In connection with the recent experimental discoveries on photo-enhancements of the electronic conductivity and the quasi-static electric susceptibility in SrTiO3, we theoretically study a photogeneration mechanism of charged ferroelectric domains in this perovskite-type quantum dielectric. The photogenerated electron, being quite itinerant in the 3d band of Ti4+, is assumed to couple weakly but quadratically with soft-anharmonic T1u phonons in this quantum dielectric. This photogenerated electron is also assumed to couple strongly but linearly with the breathing(A1g) type high-energy phonons. Using a discrete model, we will show that these two types of electron-phonon couplings result in two types of polarons, a “super-para-electric large polaron” with a quasi-global parity violation, and an “off-center type self-trapped polaron” with only a local parity violation. We will also show that this super-para-electric large polaron is nothing else but a singly charged (eâ) and conductive ferroelectric domain with a quasi-macroscopic size. This large polaron is also shown to aggregate with other same polarons, resulting in large bipolarons and their clusters.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 112, Issues 1â4, April 2005, Pages 271-274
Journal: Journal of Luminescence - Volume 112, Issues 1â4, April 2005, Pages 271-274
نویسندگان
Y. Qiu, K. Nasu,