Electronic excitations in ZnWO4 and Zn x Ni1−x WO4 (x = 0.1 − 0.9) using VUV synchrotron radiation
Tóm tắt
The photoluminescence spectra and luminescence excitation spectra of pure microcrystalline and nano-sized ZnWO4 as well as the Zn
x
Ni1−x
WO4 solid solutions were studied using vacuum ultraviolet (VUV) synchrotron radiation. The samples were also characterized by x-ray powder diffraction. We found that: (i) the shape of the photoluminescence band at 2.5 eV, being due to radiative electron transitions within the [WO6]6− anions, becomes modulated by the optical absorption of Ni2+ ions in the Zn
x
Ni1−x
WO4 solid solutions; and (ii) no significant change in the excitation spectra of Zn0.9Ni0.1WO4 is observed compared to pure ZnWO4. At the same time, a shift of the excitonic bands to smaller energies and a set of peaks, attributed to the one-electron transitions from the top of the valence band to quasi-localized states, were observed in the excitation spectrum of nano-sized ZnWO4.
Tài liệu tham khảo
A.W. Sleight, Acta. Crystallogr. B 28, 2899 (1972)
H. Wang, F.D. Medina, D.D. Liu, Y.D. Zhou, J. Phys.-Condens. Mat. 6, 5373 (1994)
H. Kraus et al., Phys. Lett. B 610, 37 (2005)
H. Grassmann, H.G. Moser, E. Lorenz, J. Lumin. 33, 21 (1985)
A.A. Kaminskii, Appl. Optics 38, 4533 (1999)
A.R. Phani, M. Passacantando, L. Lozzi, S. Santucci, J. Mater. Sci. 35, 4879 (2000)
A. Kuzmin, R. Kalendarev, A. Kursitis, J. Purans, J. Non-Cryst. Solids 353, 1840 (2007)
H.M. Pask, Prog. Quant. Electron. 27, 3 (2003)
L.C. Hsu, Am. Mineral. 66, 298 (1981)
A.L.M. de Oliveira et al., Dyes Pigments 77, 210 (2008)
V.N. Kolobanov et al., Nucl. Instrum. Meth. A 486, 496 (2002)
V. Nagirnyi et al., Nucl. Instrum. Meth. A 486, 395 (2002)
V. Pankratov, L. Grigorjeva, D. Millers, S. Chernov, S. Voloshinovskii, J. Lumin. 94, 427 (2001)
L. Grigorjeva, D. Millers, S. Chernov, V. Pankratov, A. Watterich, Radiat. Meas. 33, 645 (2001)
M. Itoh, T. Katagiri, T. Aoki, M. Fujita, Radiat. Meas. 42, 545 (2007)
Z. Lou, J. Hao, M. Cocivera, J. Lumin. 99, 349 (2002)
V.B. Mikhailik, H. Kraus, G. Miller, M.S. Mykhaylyk, D. Wahl, J. Appl. Phys. 97, 083523 (2005)
G. Huang, Y. Zhu, Mater. Sci. Eng. B-Adv. 139, 201 (2007)
A. Kalinko, A. Kuzmin, J. Lumin. 129, 1144 (2009)
P.F. Schofield, K.S. Knight, G. Cressey, J. Mater. Sci. 31, 2873 (1996)
G. Zimmerer, Radiat. Meas. 42, 859 (2007)
V. Pankratov, M. Kirm, H. von Seggern, J. Lumin. 113, 143 (2005)
H. Weitzel, Z. Kristallogr. 144, 238 (1976)
R.D. Shannon, Acta Crystallogr. A 32, 751 (1976)
L.N. Limarenko, A.E. Nosenko, M.V. Pashkovskii, D.-L.L. Futorskii, Influence of structural defects on physical properties of tungstates. (Vysha Shkola, Lvov, 1978)
M. Itoh, N. Fujita, Y. Inabe, J. Phys. Soc. Jpn. 75, 084705 (2006)
A. Kalinko, A. Kuzmin, R.A. Evarestov, Solid State Commun. 149, 425 (2009)
E. Orhan et al., J. Solid State Chem. 178, 1284 (2005)