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M. Maazaz

Bio: M. Maazaz is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Crystal structure & Metaphosphate. The author has an hindex of 6, co-authored 16 publications receiving 165 citations.

Papers
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Journal ArticleDOI
TL;DR: The relationship between crystal structures and luminescent properties of the Ag M (PO 3 ) 3 (M =Mg, Zn, Ba) polyphosphates are reported in comparison with those of AgPO 3.

32 citations

Journal ArticleDOI
TL;DR: In this paper, a combination of X-ray crystal diffraction and vibrational spectroscopy was used to synthesize and study single crystals of lanthanum metaphosphate MLa(PO3)4 (M=Na, Ag).

26 citations

Journal ArticleDOI
TL;DR: The dissolution kinetics of a series of phosphate glasses with the compositions 50P2O5-15ZnO(35−x)PbO-xCdO (x=20 and 35) and (100−y) have been studied in aqueous solution as discussed by the authors.
Abstract: The dissolution kinetics of a series of phosphate glasses with the compositions 50P2O5–15ZnO–(35−x)PbO–xCdO (x=20 and 35) and (100−y)[50P2O5–15ZnO–15PbO–20CdO]–yAl2O3 (y=6 and 8) have been studied in aqueous solution. The dissolution process of aluminium free metaphosphate glasses is interpreted as hydration of glass surface with a congruent dissolution for x=35 and controlled by both mechanisms with incongruent dissolution for x=20. The addition of Al2O3 in metaphosphate glass (x=20) considerably improves the corrosion resistance. The dissolution kinetics are strongly depending on the leaching solution temperature with linear and non-linear behavior at 50 and 90 °C, respectively. This effect can be interpreted in relation to the acidity change of leaching solution and the insoluble thin layer formation on glass surface. The hydrolysis dissolution mechanism can be explained taking into account the increase of cross-linking of the short polyphosphate chains inducing a stiffness of the glass network as alumina content increases. The y=8 glass exhibits a dissolution rate in order of 10−9–10−10 g cm−2 min−1 at room temperature.

14 citations

Journal ArticleDOI
TL;DR: In this article, the luminescence of silver ions was reported in metaphosphate of composition Ag0.07Na0.93Y(PO3)4 using flux method.

10 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, three different broadband sensitization concepts for optically active erbium ions are reviewed: silicon nanocrystals, with absorption over the full visible spectrum, efficiently couple their excitonic energy to Er3+, silver-related defect states in sodalime silicate glass, and organic cage complexes coordinated with well-chosen chromophores serve as broadband sensitizers in the visible.
Abstract: Three different broadband sensitization concepts for optically active erbium ions are reviewed: 1) silicon nanocrystals, with absorption over the full visible spectrum, efficiently couple their excitonic energy to Er3+, 2) silver-related defect states in sodalime silicate glass have absorption in the blue and transfer energy to Er3+, and 3) organic cage complexes coordinated with well-chosen chromophores serve as broadband sensitizers in the visible. Energy transfer rates, efficiencies, and limiting factors are addressed for each of these sensitizers. Implications of the use of strong sensitizers for planar waveguide design are illustrated by using a model for the sensitizing effect of ytterbium.

258 citations

Journal ArticleDOI
TL;DR: The photoluminescence of Er3+ in borosilicate glass is strongly enhanced by the presence of silver as discussed by the authors, and it is possible to increase the excitation efficiency by up to a factor of 70 when excited at 488 nm.
Abstract: The photoluminescence of Er3+ in borosilicate glass is strongly enhanced by the presence of silver Samples prepared by a combination of erbium ion implantation and Na+↔Ag+ ion exchange show an increase of the Er3+ excitation efficiency of up to a factor 70 when excited at 488 nm Excitation of Er3+ is possible over a broad wavelength range in the near ultraviolet and visible Our data suggest that absorption of light occurs at a silver ion/atom pair or similar defect, followed by energy transfer to Er3+ We can exclude that silver nanocrystals are part of the dominant excitation mechanism, neither via local field enhancement effects due to their surface plasmon resonance nor via absorption and subsequent energy transfer to Er3+

194 citations

Journal ArticleDOI
TL;DR: The photoluminescence properties of a silicate glass coactivated with silver and erbium ions were studied in this article, where the broad emission of silver related species in the visible region of the spectrum has been studied in correlation with the non-resonant excitation of the ion.
Abstract: The photoluminescence properties of a silicate glass coactivated with silver and erbium ions were studied. Absorption and photoluminescence spectra allowed to distinguish in the glasses several active species related to the silver, whose ratio depends on heat treatment and silver concentration. The broad emission of silver related species in the visible region of the spectrum has been studied in correlation with the nonresonant excitation of the erbium ions. The comparison of the excitation spectra of silver and erbium shows that the erbium ions are excited through radiative and nonradiative energy transfer from small silver aggregates.

125 citations

Patent
07 Dec 2005
TL;DR: In this article, LiCoO2 layers in a pulsed-dc physical vapor deposition process are presented, which can provide a low-temperature, high deposition rate deposition of a crystalline layer of LiO2 with a desired or orientation.
Abstract: In accordance with the present invention, deposition of LiCoO2 layers in a pulsed-dc physical vapor deposition process is presented. Such a deposition can provide a low-temperature, high deposition rate deposition of a crystalline layer of LiCoO2 with a desired or orientation. Some embodiments of the deposition addresses the need for high rate deposition of LiCoO2 films, which can be utilized as the cathode layer in a solid state rechargeable Li battery. Embodiments of the process according to the present invention can eliminate the high temperature (>700°C) anneal step that is conventionally needed to crystallize the LiCoO2 layer. Some embodiments of the process can improve a battery utilizing the LiCoO2 layer by utilizing a rapid thermal anneal process with short ramp rates.

114 citations

Patent
14 Jun 2006
TL;DR: In this paper, the authors proposed a method for fabricating high performance thin-film batteries on metallic or polymeric substrates by using an appropriate barrier layer composed of barrier sublayers.
Abstract: The present invention relates to apparatus, compositions and methods of fabricating high performance thin-film batteries on metallic substrates, polymeric substrates, or doped or undoped silicon substrates by fabricating an appropriate barrier layer composed, for example, of barrier sublayers between the substrate and the battery part of the present invention thereby separating these two parts chemically during the entire battery fabrication process as well as during any operation and storage of the electrochemical apparatus during its entire lifetime. In a preferred embodiment of the present invention thin-film batteries fabricated onto a thin, flexible stainless steel foil substrate using an appropriate barrier layer that is composed of barrier sublayers have uncompromised electrochemical performance compared to thin-film batteries fabricated onto ceramic substrates when using a 700° C. post-deposition anneal process for a LiCoO 2 positive cathode.

112 citations