I need some documents, papers , articles about  optical and electric properties
of ZnO-doped with Co, Li, Mg.

Specially,
1)A. Valentini, F. Quaranta, M. Rossi, L. Vasanelli "Structural
properties of ZnO films prepared by r.f. sputtering for optical
applications" Thin Solid Films vol.175 (1989) p.255
2)A. Valentini, F. Quaranta, L. Vasanelli "Dielectric zinc oxide films
characterization for optical waveguide" Proceeding SPIE vol.1125 " Thin
Film in Optics" (1989) p.36
3)G. Sberveglieri, P. Nelli, S. Groppelli, A. Valentini, F. Quaranta,
L.Vasanelli "Oxygen gas sensing characteristics at ambient pressure of
undoped and Li doped ZnO sputtered thin films" Material Science and
Engeenering B vol.7 (1990) p.63
4)A. Valentini, F. Quaranta, L. Vasanelli, R. Piccolo "Optical
properties of Li doped ZnO films" Proceeding SPIE vol.1400 "Optical
Fabrication and Testing" (1990) p.164
5)A. Valentini, F. Quaranta, M. Rossi, C.Battaglin "Preparation and
characterization of Li doped ZnO films" Journal of Vacuum Science and
Technology A vol.9 n.2 (1991) p.286
6)G. Sberveglieri, S. Groppelli, P. Nelli, F. Quaranta, A. Valentini, L.
Vasanelli "Oxygen gas sensing characteristics for ZnO(Li) sputtered thin
films" Sensor and Actuators B, vol. 7 (1992) p.747
7)F. Quaranta, A. Valentini, F.R. Rizzi, G. Casamassima "Dual ion beam
sputter deposition of ZnO films" Journal of Applied Physics vol.74 n.1
(1993) p.244
8)A. Valentini, F. Quaranta, M. Penza, F.R. Rizzi "The stability of zinc
oxide electrodes fabricated by dual ion beam sputtering" Journal of
Applied Physics vol. 73 n.3 (1993) p.1143

Thanks in advance,
N./ H. Dzung.