کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9586336 | 1505936 | 2005 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A theoretical investigation of 4fâ5d transition of trivalent rare earth ions in fluorides and complex oxides
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
We have investigated 4fnâ4fnâ15d excitation energies for trivalent rare earth ions in LaF3, LiYF4, YF3, LiGdF4, K2YF5, YAlO3, LaBO3 and YPO4 using a spin density functional procedure based on the atomic sphere approximation (computer code ASW). The local relaxation of the activator ions in the host lattices has been calculated by the projector augmented wave method (computer code VASP). The experimentally observed 4fnâ4fnâ15d excitation energies are shown to depend linearly on the calculated energy difference between the one-electron f- and d-like states of the rare earth ions Îεfâd. The linear relationship, ÎE=mÎε+εshift, involves two empirical parameters m and εshift. m is found to be the same for all ions and hosts, and εshift is different for the different ions but independent of the host lattice. In the present case, m and εshift have been determined empirically by a least-square fitting procedure from the experimental and calculated ÎE for the hosts LaF3, YF3 and LiYF4. The error of the predicted excitation energies is lower than 0.3 eV for the systems. This error increases up to 0.6 eV for some heavy rare earth ions for which the calculated occupied one-electron f-like states overlap energetically with the host valence band states (Er and Tm in the hosts LaF3, YPO4 and LiYF4).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 114, Issues 3â4, September 2005, Pages 255-266
Journal: Journal of Luminescence - Volume 114, Issues 3â4, September 2005, Pages 255-266
نویسندگان
M. Stephan, M. Zachau, M. Gröting, O. Karplak, V. Eyert, K.C. Mishra, P.C. Schmidt,