Ce mémoire traite des différentes étapes d'amélioration d'un procédé chimique industriel dont le sujet est la fabrication de fondant boraté à partir des réactifs sous forme de sels inorganiques. Il présente les trois objectifs principaux qui ont été ciblés pour l'amélioration du procédé, c'est-à-dire l'atteinte d'une stoechiométrie précise, l'amélioration du contrôle qualité ainsi que l'amélioration de l'efficacité de production d'une des étapes du procédé de fabrication. Il discute d'hypothèses, de problématiques et de solutions envisageables pour l'amélioration continue du processus de fabrication du fondant boraté. / The following work discusses the improvement of a chemical process that consists in the manufacture of the borate fluxes from inorganic salts. This work discusses the three main objectives of this study. These are the achievements of a precise and accurate stoichiometry, the improvement of the quality control process and lastly the improvement of the efficiency of a production step, particularly the mixing of the reagents. This work discusses hypothesis, problematics and diverse solutions that would improve the fabrication process.

No description available.

Différentes techniques spectroscopiques (impédancemétrie électrique, RMN, IR et Raman) ont été utilisées pour étudier la mobilité ionique de deux séries de verres binaires de borate d’alcalins (Li₂O-B₂O₃ et Na₂O-B₂O₃) dans une large gamme de composition en relation avec la structure, aussi bien dans l’état solide que dans l’état fondu. Nous avons ainsi établi un bilan complet de l’évolution de la structure du réseau vitreux à température ambiante en fonction de la teneur en oxyde d’alcalin M₂O. Alors que B₂O₃ n’est formé que d’unités BO₃, organisées en anneaux boroxol reliés par des chaînes, l’ajout d’alcalins entraîne l’apparition d’unités BO₄- incorporées dans différents groupements borate. Parallèlement, les chaînes et les boroxols disparaissent progressivement. A partir de 20% en M₂O, les alcalins commencent à jouer un rôle de modificateurs de réseau vitreux en cassant des liaisons, entrainant la formation d’oxygènes non-pontants (NBO). Leur proportion augmente rapidement de telle sorte qu’à partir de 40% de M₂O, la teneur en BO₄- rediminue. L’association de deux dispositifs de mesure de l’impédance complexe a permis d’obtenir des valeurs fiables de la conductivité sur un intervalle de température très étendu allant du solide jusqu’à l’état fondu. En dessous de Tg, la conductivité statique suit une loi d’Arrhenius. Sa valeur augmente avec la teneur en M₂O, toutefois, deux changements de régime sont observés : le premier vers 32% de M₂O coïncide avec l’anomalie de bore et peut être relié à la formation d’un nombre important de NBO, le second, est observé dans la série Na vers 10-20% de Na₂O et serait provoqué par une compaction du réseau. En passant à l’état fondu, la conductivité augmente de façon considérable et suit une loi VFT. Nous avons observé que l’anomalie de bore persiste à l’état fondu, mais se déplace vers les basses teneurs en M₂O. / Different spectroscopic techniques (electrical impedancemetry, NMR, IR and Raman) have been used to study ionic mobility of two series of binary alkaline borate glasses (Li₂O-B₂O3 and Na₂O-B₂O₃) in a wide range of composition in relation to their structure, both in the solid and molten state. We have thus established a complete description of the structural evolution of the vitreous network at ambient temperature as a function of the alkaline oxide M₂O content. While B₂O₃ is only formed of BO₃ units, organized in boroxol rings linked by chains, the alkaline addition leads to the appearance of BO₄- units incorporated in different borate groups. At the same time, chains and boroxols disappear gradually. From 20% M₂O, the alkalines start to play the role of vitreous network modifiers by breaking bonds, resulting in the formation of non-bridging oxygens (NBO). Their proportion increases rapidly so that, from 40% M₂O, the BO₄- content decreases. The association of two devices for measuring the complex impedance enabled us to obtain reliable values of the conductivity over a very extended temperature range from the solid to the molten state. Below Tg, the static conductivity follows Arrhenius law. Its value increases with the M₂O content, however, two changes are observed: the first towards 32% M₂O coincides with the so-called boron anomaly and can be related to the formation of a large number of NBO, the second, is observed in the Na series towards 10-20% Na₂O and is caused by network compaction. When passing to the molten state, the conductivity increases considerably and follows a VFT law. We observed that the boron anomaly persists in the molten state, but moves to lower M₂O contents.

L’éclairage par « LEDs blanches » est devenu un enjeu majeur afin d’élaborer des dispositifs à bas coût, produisant une lumière confortable pour l’œil en évitant de forte composante bleue nocive pour la vue et la santé. A l’Institut Néel, nous développons un nouveau type de luminophores à base de poudres d’aluminoborate d’yttrium. Le caractère innovant de ces poudres est de produire une large bande d’émission dans l’ensemble du spectre visible, à partir de défauts structuraux présents dans la matrice amorphe. Ainsi ces luminophores permettraient de générer un éclairage blanc sous l'excitation de LED émettant dans le proche UV (370-390 nm). De plus, ces matériaux n’ont pas de lanthanides, ce qui réduit leur coût.Les luminophores d’aluminoborate d’yttrium ont dans un premier temps été préparés par la méthode des précurseurs polymériques, impliquant plusieurs étapes de recuits sous atmosphères contrôlées à des températures relativement élevées (700-740°C). Le travail de thèse a porté dans un premier temps sur la mise au point de la synthèse par voie sol-gel. Ces travaux ont permis de réduire simultanément les durées du procédé et les températures des traitements thermiques (450-650°C), ainsi que la perte de masse globale par décomposition des fonctions organiques des précurseurs.Par analyses thermiques (ATD, ATG) couplée à la spectrométrie de masse et RMN 13C, nous avons caractérisé la présence de résidus carbonés dans les poudres lorsqu’elles présentent de la luminescence. Néanmoins, une partie de ces résidus carbonés se trouvent sous forme de carbone pyrolytique (carbones aromatiques) qui entrainent une réabsorption partielle de la luminescence émise dans le visible, entrainant ainsi une diminution de l’intensité d’émission. Les caractérisations structurales (DRX, FTIR, RMN) menées sur les poudres ont montré que la première phase cristalline apparaissant pour les deux méthodes de synthèse est une phase d’aluminoborate Al4B2O9. L’étude par Fonction de Distribution de Paires (PDF) montre que la matrice aluminoborate amorphe présente un ordre local proche de la phase Al4B2O9, à savoir une organisation tridimensionnelle cyclique de métaux pontés par des ligands oxo ou hydroxo de 6 à 10 chaînons. D’autre part, sur la base des résultats RMN 13C, l’yttrium semble garder dans sa sphère de coordination des ligands propionates jusqu’à hautes températures. Par ailleurs, la présence d’espèces radicalaires dans les poudres luminescentes a été mise en évidence par résonnance paramagnétique électronique. Un ensemble de mesures à différentes fréquences, en mode continu et pulsé, ont permis d’attribuer ces espèces à des radicaux carbonés. Les études de photoluminescence non-résolues et résolues en temps, couplées à des analyses de thermoluminescence ont mis en évidence la présence de plusieurs espèces luminescentes présentant essentiellement des propriétés de fluorescence (durée de vie de quelques ns) mais aussi une très faible part de phosphorescence (durée de vie de la ms à plusieurs s). Les poudres synthétisées par voie sol-gel présentent un rendement quantique interne d’environ 30 %.Aux vues des différentes analyses, les poudres luminescentes synthétisées par voie sol-gel semblent contenir deux types de résidus carbonés : l’un à l’origine des propriétés de photoluminescence et l’autre défavorable (carbone pyrolytique piégé) car absorbant partiellement l’émission de luminescence. En conclusion, nous proposons un mécanisme de photoluminescence extrinsèque, basé sur des centres carbonés dispersés au sein de la matrice minérale, favorisant majoritairement la fluorescence dans le bleu (bande centrée vers 430 nm) et dans le vert (bande centrée vers 500 nm) mais aussi une faible proportion de phosphorescence émettant dans la même gamme de longueurs d’onde. / White solid state lighting is recognized as a major disruptive technology with an urgent need of low coast prices, associated to good color quality, confortable for eyes, by reducing the bluish harmful contribution of “cold” lighting. At Néel Institute, we develop a new type of phosphors based on yttrium aluminoborate powders. These innovating powders exhibit a large emission band on the whole visible range, arising from structural defects in the amorphous matrix. Thus, with a single phosphor, one can generate warm white lighting through the excitation of LEDs emitting in the near UV (370-390 nm). Moreover, these phosphors don’t possess lanthanides, making them less expensive.The powders synthesized by chimie douce routes, are annealed under controlled atmosphere. The yttrium alominoborate phosphors were first prepared by the polymercic precursor method. This synthesis road involved several steps and relatively high annealing temperatures (700-740°C). This thesis was focused on the sol-gel synthesis method. By this work, the duration process, the annealing temperature (450°C-650°C), and the global mass loss incoming from the organic precursors decomposition were significantly reduced.Thermal analysis (TDA-TG) coupled with mass spectrometry and 13C RNM show residual carbon groups in luminescent powders. Nevertheless, one part of the residual carbons is pyrolytic carbon (aromatic carbon), which leads to partial re-absorption of the visible emitted luminescence, and thus induces a decrease of the emission intensity.The structural characterizations of yttrium aluminoborate powders (XRD, FTIR, NMR) show that Al4B2O9 aluminoborate phase, is the first appearing crystalline phase during the increase of calcination temperature. The Pair Distribution Function (PDF) study demonstrates that amorphous aluminoborate matrix exhibit a short range ordering close to Al4B2O9 phase: a cyclic tridimensional organization of metal bridges by oxo or hydroxo ligands. On the other hand, based on 13C NMR results, yttrium seems to conserve propionate ligands in its coordination sphere until high temperature. Otherwise, the presence of radical species was evidenced in luminescent powders by electronic paramagnetic resonance. A set of measurements performed at different frequencies, in continuous and pulsed modes, allows attributing that species to carbon radicals. The presence of several luminescence species exhibiting essentially fluorescence properties (ns life time) and very weak phosphorescence emission (ms and s lifetime) was shown by the means of photoluminescence studies steady-state and time resolved coupled to thermoluminescence analysis. The powders synthesized by sol-method exhibit a 30 % internal quantum yield.Thanks to the different characterizations, luminescent powders synthesized by the sol-gel route seem to contain two types of residual carbons: one at the origin of the luminescence properties (carbon-related radicals) while the other, pyrolytic carbon, is damaging as it absorbs partially the luminescence emission. To conclude, we suggest an extrinsic mechanism for the photoluminescence, which is based on carbon centers dispersed inside the mineral matrix, favoring mainly fluorescence in blue (430 nm) and green emissions (500 nm) associated with a weak phosphorescence emission in the same emission range.

Transparent glasses embedded with ferroelectric/nonlinear optic crystallites have been in increasing demand as these exhibit promising physical properties. These could be fabricated in large sizes and shapes with high optical homogeneity accompanied by high degree of transparency over a wide range of wavelengths of light. Amongst a variety of glasses that are known, borate-based glasses are of particular interest owing to their greater transparency, good chemical and mechanical stability, low materials cost, and useful electrical and dielectric properties. Keeping the potential multifarious applications of transparent glass-microcrystal composites in view, BaO-0.5Na2O-4.5B2O3, BaO-0.5Li2O-4.5B2O3, SrO-0.5Li2O-4.5B2O3, 3BaO-3TiO2-B2O3 and Li2O-3B2O3 glasses and glass-microcrystal composites were fabricated. These glasses on controlled heat treatment at appropriate temperatures yielded BaNaB9O15, BaLiB9O15, SrLiB9O15, Ba3Ti3B2O12 and LiB3O5 crystalline phases, respectively. Further transparent surface crystallized BaO-0.5Na2O-4.5B2O3 glasses were fabricated using ultrasonic treatment and their thermal properties have been investigated in detail using differential scanning calorimetry. It is observed that these glasses were homogeneously crystallizing on the surfaces after Ultrasonic treatment which can be exploited for planner wave-guide applications. Glass forming ability, thermal stability, glass-transition behavior, crystallization kinetics and viscosity of these glasses were studied extensively using various methods and rationalized by invoking various models. The above glasses have been characterized for their dielectric and electrical relaxation properties (as these properties are related to their electro-optic and non-linear optical properties) over 30- 600oC temperature range and frequencies (100 Hz -10 MHz) that are normally of interest in the applications of these materials. Several interesting features such as high ionic conductivity, marginally low dielectric loss and high dielectric constant behavior along with low thermal coefficient of dielectric constant were observed in these glasses and were rationalized using various models. The combination of these dielectric characteristics suggests that these are potential candidates for electrical energy storage device applications.

No description available.

The primary objective of this study was to investigate mould growth resistance of different types of wood products which include the sheathing and framing within full scale wall assemblies. Secondary objectives were to investigate the difference in mould growth resistance between borate-treated and untreated wood products as well as provide information about mould growth under different temperature and humidity conditions for treated and untreated wood products. <br /><br /> The objective of the study is to better understand mould growth, and to examine the effects of varying high moisture conditions on wooden products and the mould growth which may result. More importantly this will be examined on full scale wall assemblies; to date mould growth studies have only been performed within a laboratory on small samples of materials. Moreover, this study recreates the conditions which evidently cause mould growth on full scale wall assemblies. Tests were performed within a climate chamber on three full scale wall assemblies. The original scope of this study included an examination of the sheathing and framing components within a full scale wall assembly, however this study will focus mainly on the sheathing. <br /><br /> Results of this study indicate that the relative humidity conditions needed for mould growth on wood are higher than originally believed (i. e. , significantly greater than 80%RH). During the first eight weeks of test number one the relative humidity at the surface of the sheathing was held constant at 95% and little mould growth was observed on the untreated sheathing (mould growth index of 3 or less); little or no mould growth on the treated sheathing (mould growth index of 1 or less). The second and third tests demonstrated that the presence of liquid water greatly accelerated the time to germinations, the amount of mould growth (up to a mould growth index of 6), and the rate of mould growth. All three tests clearly showed that borate-treatment reduced the amount of mould growth; however, the concentration of borate-treatment, and the types of materials treated, does affect the resistance of mould growth. Furthermore, there was some evidence to suggest Borate treatments of the plywood increased the time to germination significantly, from a few weeks to 16 weeks in this study, but once mould growth was initiated, the rate of mould growth was similar to that of the untreated plywood. Two mathematical models to determine mould growth were examined: Viitanen and WUFIBIO (Sedlbauer). Viitanen?s model predicted time to germination and rate of growth rate well for untreated plywood, and WUFIBIO predicted time to germination but not the growth rate. It was also found both models err on the side of caution in predicting mould growth. <br /><br /> Recommendations include improvements to the test method and producers, and for future work.

The present work investigates the tribological properties of solid particles as lubricant additives in lubricants. Two types of solid particles, Ceria nanoparticles (CeO2) and Zinc borate ultrafine powders (ZB UFPs), were used as the lubricant additives in this study. The friction and wear behaviours of these lubricant additives in different base lubricants were identified. With an appropriate application of these solid lubricant additives, the friction reduction and wear resistance properties of the lubricant have been successfully improved. Without assistance of surfactant or surface modification, the two types of solid particles behave very differently. Evident performance was observed that pure ZB UFPs were capable of considerably reducing the friction coefficient of sunflower oil and liquid paraffin when they were used as a lubricant additive without further treatment. On the contrary, CeO2 nanoparticles did not show noticeable contribution to friction reduction when they were used as the only additive in water. Only when surfactant Sorbitan monostearate was employed to enhance the dispersibility of CeO2 nanoparticles in water, the application of this additive was capable of reducing friction coefficient of the water based lubricant effectively. Surface modification of the solid particles was carried out to improve the dispersibility of these particles in base lubricants. Oleic acid (OA) and Hexadecyltrimethoxysilane (HDTMOS) were selected as the modification agents. Modified CeO2 nanoparticles and ZB UFPs revealed outstanding wear resistance property. An improvement of up to 15 times was identified although this improvement on wear resistance, in this case, was often companied by a rise in friction coefficient. Tribo-films generated by tribo-chemical reaction were observed on most of the worn surfaces and the formation of this tribo-film appeared to have played an important role in the friction and wear behaviours of a system. A tenacious tribo-film with good surface coverage was only generated on the worn surface when HDTMOS modified solid particles were used as lubricant additives. The mechanical properties and elemental composition of the tribo-film were studied with nano-indentation and energy-dispersive X-ray spectroscopy (EDS). Finally, based on the experimental evidence, different functionalities of CeO2 nanoparticles and ZB UFPs as solid lubricant additives were recognized.

Esse trabalho descreve a caracterização térmica, estrutural e elétrica do sistema vítreo 50B203-(50-x)PbO-xLiF com x variando de 0,0 a 50,0. A técnica de calorimetria diferencial exploratória (DSC) foi utilizada na determinação das temperaturas características. A difratometria de raios x foi utilizada na detecção e identificação de fases cristalinas originadas durante a síntese ou durante o processo de aquecimento das amostras. As técnicas de espectroscopia Raman e Ressonância Magnética Nuclear (RMN) foram utilizadas na obtenção de informações estruturais da ordem a curto alcance em função da composição das amostras. A técnica de espectroscopia de impedância complexa foi utilizada na determinação das condutividades elétrica em função da quantidade de LiF e da temperatura. Amostras vítreas sem a presença de fases cristalinas foram obtidas para composições contendo no máximo 40moI % de LiF. Através da análise da medida de densidade, foi possível constatar que o aumento da quantidade de LiF leva a formação de uma estrutura mais aberta. A análise do espectro Raman das amostras vítreas mostrou que com o aumento da concentração de LiF, ocorre uma mudança significativa nas unidades estruturais borato presentes nas amostras. Na amostra vítrea contendo 40 mol% de LiF observou-se a existência de uma superunidade estrutural formada por diferentes unidades borato. Apesar dessa variação das unidades borato, as medidas de RMN do 11B mostraram que a razão entre as unidades trigonal B03 e tetraédrica B04 permanece praticamente constante em todo intervalo de composição analisada. A condutividade elétrica aumenta à medida que a concentração de LiF aumenta devido ao aumento do numero de portadores de carga. A 330&#176;C uma condutividade de 3,55 x 10-5 S/cm foi medida para a amostra contendo 40 moI % de LiF. Utilizando as amostras contendo 40 e 45 mol% de LiF preparadas e caracterizadas durante a realização desse trabalho, foi possível construir um dispositivo para ser utilizado na demonstração do processo de condução elétrica em materiais vítreos condutores para alunos do ensino médio / This work describes the thermal, structural and electric characterization of 50B203-(50-x)PbO-xLiF glass system with x varying from 0,0 to 50,0. The differential scanning calorimetry (DSC) technique was used to determine the glass transition and the crystallization temperatures. The X-ray diffraction technique was used to detect and in the identification of the crystallized phases present on the glassy samples after the melt and during the heating. The Raman spectroscopy and the Nuclear Magnetic Resonance techniques were used in order to verify the structural changes induced by the substitution of PbO by LiF on the anionic borate units and on the B03/B04 species ratio. The impedance complex spectroscopy technique was used to evaluate the variation of the electrical conductivity and activation energy as a function of the LiF content. Homogenous glassy sample containing less than 45 mol % of LiF without any trace of crystallization were obtained. The analysis of the Raman spectra shows that as the amount of LiF increases the concentration of anionic borate species changes and that these changes are an indicative of the formation of B-F bonds. However, according to the 11B NMR data, these structural rearrangement should be of such nature that the ratio sup>[3]B/[4]B is near1y invariant. As expected, the electrical conduction increases as the amount of LiF increases because the number of carriers increases. At 330&#176;C; , the conductivity varies from 3.93 x 10-10 (S/cm) for the sample without LiF to 3.55 x 10-5(S/cm) for the sample containing 40 mol % of LiF. The activation energy (Ea) varied respectively from 1.55 eV to 0.97 eV. Using the glassy samples with 40 and 45 mol% of LiF, we could built a set up that can be used to demonstrate the electrical conduction process on glass materials to high school students

As amostras de vidro aluminoborato de bário (BABAL), obtido a partir da estrutura 20 Al2O3. 50 B2O3. 30 BaO mol% dopadas com manganês foram preparadas e caracterizadas pelas técnicas de absorção óptica (AO), ressonância paramagnética eletrônica (RPE) e termoluminescência (TL). O presente estudo está centrado nos íons manganês e nas suas interações com os vizinhos mais próximos que são os átomos de oxigênio e outros íons que o circundam dentro da matriz vítrea. As amostras do vidro BABAL não dopadas e irradiadas com radiação gama apresentam uma banda de absorção óptica com um máximo em 555 nm, a qual foi associada ao BOHC (boron hole center). As amostras do vidro BABAL dopadas com MnO e MnO2 não apresentaram uma mudança significativa com a radiação, pois a janela óptica relativamente reduzida não permite observar diretamente as principais transições referentes ao Mn2+. Para os vidros BABAL dopados com baixas dopagens de MnO2 (< 0,1 mol%) foi demonstrada a redução de Mn4+ para Mn3+ e posteriormente para Mn2+ até atingir a distribuição de equilíbrio nos estados de oxidação. Assim, a utilização dos diagramas de Tanabe e Sugano associados aos íons Mn2+ e Mn3+ em sítios octaédricos forneceram os resultados Mn2+=12610 ±100 cm-1 e Mn3+=21440 ±100 cm-1, respectivamente, para os vidros BABAL dopados com íons de manganês. Para os vidros Li2O.CaF2.B2O3 produzidos e caracterizados por Rao et al. calculamos a intensidade do campo cristalino, obtendo os resultados para o íon Mn2+ é 13740 ± 100 cm-1 e para o íon Mn3+ é 20030 ± 100 cm1-. Para o caso de amostras BABAL não irradiadas observou-se um aumento do pico de uma banda de absorção na região compreendidas entre os comprimentos de onda de 360 a 650 nm quando foram adicionadas quantidades crescentes de manganês. Aumentando a dopagem com MnO ocorreu um deslocamento do pico de 460 para 470 nm devido à introdução de pequenas distorções adicionais na estrutura da rede vítrea causado pela presença do íon Mn2+. As amostras dopadas com MnO2 apresentaram o mesmo comportamento para diferentes concentrações de dopantes, mas não apresentam deslocamento do pico central em 465 nm, mostrando que a adição dos íons Mn4+ introduz menores distorções à rede vítrea. O espectro RPE dos vidros BABAL dopado com MnO2 e MnO apresenta quatro ressonâncias (g1 = 5,1; g2 = 4,3; g3 = 3,0 e g4 = 2,0) que são consistentes com as impurezas contidas nestas amostras. A curva TL para as amostras irradiadas dos vidros BABAL dopados com manganês apresentou dois picos bem definidos às temperaturas de 140 0C e 302 0C, respectivamente, atribuídos ao centro de elétron do boro (BEC) e centro de buraco do boro (BOHC) e uma emissão mais fraca adicional em 4000C associado a BOHC´s na vizinhança de íons de manganês localizados no centro de unidades estruturais tetragonais. / Samples of barium aluminobonate (BABAL) glasses of composition 20 Al2O3. 50 B2O3. 30 BaO mole% doped with manganese were prepared and characterized using the techniques of optical absorption (OA), electron paramagnetic resonance (EPR) and thermoluminnescence (TL). This study is concerned about the different manganese ions and their interactions with the nearest neighboring atoms of oxygen and other ions present in the glassy matrix. The non-doped BABAL glass samples, after being gamma-irradiated show an OA maximum at the wavelength of 555 nm that was attributed to the boron-oxygen hole center (BOHC). The BABAL glass samples doped with MnO and MnO2 did not show a significant change on irradiation, because the relatively reduced optical gap did not allow to observe directly. The main transitions due to the Mn2+ ion. For the lower doping levels with MnO2 (<0.1mole%) it was demonstrated that Mn4+ was reduced to Mn3+ and then to Mn2+ until the equilibrium redox distribution was reached. Thus, using the Mn2+ and Mn3+. Tanabe-Sugano diagrams for sites having octahedral symmetry, the results of Mn2+=12610 ±100 cm-1 and Mn3+=21440 ±100 cm-1, respectively, for BABAL glasses doped with manganese. For the Li2O.CaF2.B2O3 glasses produced and characterized by Rao et al., we calculated the crystalline field parameters, yielding the results 13740 ± 100 cm-1 for the Mn2+ ion and 20030 ± 100 cm-1 for Mn3+ . Increasing manganese content in non-irradiated BABAL samples produced an increase of the absorption in the range of 360 to 650 nm and the peak shifted from 460 to 470 nm as a consequence of the introduction of small additional distortions in the glass amorphous lattice caused by the presence of Mn2+ ions. The samples doped with MnO2 presented the same behavior for different dopant concentrations but did not show any shift for the peak in 465 nm, showing that the Mn4+ ions introduce less distortion in the glass lattice. The EPR spectra of the BABAL glasses doped with MnO2 exhibit four resonances (g1=5.1; g2=4.3; g3=3.0 and g4=2.0), consistent with the manganese and iron impurities also present in the samples. The TL of the irradiated BABAL samples doped with manganese presented two well defined peaks at the temperatures of 140 0C and 302 0C, respectively, attributed to the boron-electron center (BEC) and BOHC and an additional weak emission at 400 0C that was associated to BOHC´s in the vicinity of manganese into tetrahedral structural units.