Role Of Aluminum Research Articles

Interzeolite Conversion and the Role of Aluminum: Toward Generic Principles of Acid Site Genesis and Distributions in ZSM-5 and SSZ-13

The performance of zeolite catalysts depends not only on the strength and number of Bronsted acid (or exchange) sites but also on synergistic effects derived from their proximity, in particular, an...

Critical review of the publications on the genotoxicology of aluminium salts: 1990-2018.

Since the mid-1970s, there have been many reports that purport to implicate aluminium in the aetiology of neurodegenerative disease. After several decades of research, the role of aluminium in such disease remains controversial and is not the subject of this review. However, if aluminium is implicated in such disease then it follows that there must be a toxicological mechanism or mode of action, and many researchers have investigated various potential mechanisms including the involvement of oxidative damage, cytotoxicity and genotoxicity. This paper reviews many of the publications of studies using various salts of aluminium and various genotoxicity end points, both in vitro and in vivo, with a focus on oxidative damage. The conclusion of this review is that the majority, if not all, of the publications that report positive results have serious technical flaws and/or implausible findings and consequently should contribute little or no weight to a weight of evidence (WoE) argument. There are many high-quality, Good Laboratory Practice (GLP)-compliant genotoxicity studies, that follow relevant OECD test guidelines and the European Chemicals Agency (ECHA) integrated mutagenicity testing strategy, on several salts of aluminium; all demonstrate clear negative results for both in vitro and in vivo genotoxicity. In addition, the claim for an oxidative mode of action for aluminium can be shown to be spurious. This review concludes that there are no reliable studies that demonstrate a potential for genotoxicity, or oxidative mode of action, for aluminium.

The role of aluminum and iron hydroxides in the formation of concrete properties

Aluminum and iron hydroxides, formed in the stone during the hydration of cement with the addition of special slags, significantly improve the properties of concrete. The addition of low-basic calcium aluminates CA2 and CA6 in the form of high-alumina slag, which releases a large amount of Al(OH)3 during hydration, increases the strength, density, water resistance, frost and corrosion resistance of hydraulic concrete. A compressed mixture of concrete scrap and high-alumina slag based on low-basic aluminates makes it possible to obtain durable and frost-resistant materials and pavement structures. A special nickel slag of increased basicity in a mixture with Portland cement ensures the formation of ferric hydroxide during hydration. Concrete on such Portland slag cement shows frost resistance for more than 500 cycles without special measures.

The role of aluminum and lead in the development of Alzheimer's and Parkinson's diseases

The article summarizes the data available in the literature on the toxic effects of aluminum and lead on the human brain and assesses the relationship of these effects to the etiopathogenesis of the most common neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. The accumulation of ions of these metals in the brain structures leads to chronic intoxication that is manifested by the morphological signs that are typical for Alzheimer's disease, such as deposits of β-amyloid and τ-protein mainly in the frontal and temporal regions of the cortex, and for Parkinson's disease, such as degeneration of dopamine neurons in the substantia nigra and their accumulation of α-synuclein. The most likely forms of participation of aluminum and lead ions in the mechanisms of neurodegeneration are the replacement of bivalent metal ions necessary for brain functioning, oxidative stress initiation, epigenetic modifications of histones, and increased expression of noncoding ribonucleic acids.

(Invited) Atmospheric Corrosion of Magnesium Alloys: Influence of Aluminium Content

Magnesium has gained considerable interest as a structural material for automotive and aerospace applications due to its low density and high specific strength. The use of magnesium alloys in engineering applications is, however, mainly limited by their unsatisfactory surface properties and their poor corrosion resistance. In recent years, significant improvements have been made in achieving a better corrosion resistance particularly by reducing the contents of impurities such as Fe, Cu, and Ni. Intermetallic phases, a result of the casting process, play an important role in the corrosion process. The role of these intermetallic phases has been addressed in a number of papers [1–3]. The role of aluminum in the atmospheric corrosion of magnesium alloys has less addressed in the literature [4]. Esmaily et al have shown recently that the rate of corrosion of magnesium alloys decreased when increasing the Al content. However these experiments were performed on commercial magnesium alloys produced high pressure die casting under constant RH exposure at 90% RH.In our work the corrosion behavior of binary Mg-Al alloys as well as that of commercial magnesium alloys with different aluminum contents have studied both under cyclic corrosion exposure in the laboratory and in field exposures in France and in Vietnam. Analyses of corrosion products have also been conducted. Additional in-situ measurements have been performed in order to better understand the atmospheric corrosion mechanisms of Mg alloys.An important decrease in the maximum pit depth can be observed after different laboratory exposures when increasing the aluminum content in the material. Similar results have been obtained after 9 months exposure in Field. Hence, from these results it is obvious that an increase of the aluminum concentration in Mg-Al alloys decreased the corrosion rate of the alloy. This lead in lower mass loss and less deep corrosion attacks in the magnesium grains. The analyses of corrosion products formed after the cyclic corrosion tests and field exposures revealed the presence of Magnesium carbonate and MgCO3(OH)4,4H20, respectively. In both cases magnesium hydroxide (Mg(OH)2 was also found in the corrosion products. The results will be discussed in relation with the microstructure of the cast materials. O. Lunder, J.E. Lein, S.M. Hesjevik, T.K. Aune, K. Nisancioglu, Werkstoffe und Korrosion 45 (6) (1994) 331–340. O. Lunder, J.H. Nordlien, K. Nisangliou, Corrosion Reviews 15 (3–4) (1997) 439–469.G. Song, A. Atrens, M. Dargusch, Corrosion Science 41 (1999) 249–273.M. Esmailly, D.B. Blucher, J.E. Svensson, M. Halvarson and LG Johansson, Scripta Materiala, 115 (2016), 91-96

Understanding the setting and hardening process of wollastonite-based brushite cement. Part 2: Influence of the boron and aluminum concentrations in the mixing solution

The mixing solution of wollastonite-based brushite cement is a phosphoric acid solution containing metallic cations and borax. This work complements a previous study devoted to the influence of the H3PO4 concentration, Ca/P and liquid-to-solid (l/s) ratios on the setting and hardening process of the binder by providing new insight into the role of aluminum and boron.Boron retards the setting and decreases the heat released during the process. It also contributes to reduce the macroporosity of the hardened material but yields to poor compressive strength. With aluminum in the mixing solution, the mechanical properties are greatly improved thanks to the precipitation of an amorphous aluminophosphate which increases the density of the cement matrix. But aluminum alone leads to fast setting. A joint addition of boron and aluminum to the mixing solution makes it possible to get a material with optimized properties both in fresh and hardened states.

Role of Aluminium on the Microstructure and Corrosion Behaviour of Magnesium Prepared by Powder Metallurgy Method

Much research on magnesium (Mg) emphasises creating good corrosion resistance of magnesium, due to its high reactivity in most environments. In this study, powder metallurgy (PM) technique is used to produce Mg samples with a variation of aluminium (Al) composition. The effect of aluminium composition on the microstructure development, including the phase analysis was characterised by optical microscope (OM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The mechanical property of Mg sample was performed through Vickers microhardness. The results showed that the addition of aluminium in the synthesised Mg sample formed distribution of Al-rich phases of Mg17Al12, with 50 wt.% of aluminium content in the Mg sample exhibited larger fraction and distribution of Al-rich phases as compared to the 20 wt.% and 10 wt.% of aluminium content. The microhardness values were also increased at 20 wt.% and 50 wt.% of aluminium content, comparable to the standard microhardness value of the annealed Mg. A similar trend in corrosion resistance of the Mg immersed in 3.5 wt.% NaCl solution was observed. The corrosion behaviour was evaluated based on potentiodynamic polarisation behaviour. The corrosion current density, icorr, is observed to decrease with the increase of Al composition in the Mg sample, corresponding to the increase in corrosion resistance due to the formation of aluminium oxide layer on the Al-rich surface that acted as the corrosion barrier. Overall, the inclusion of aluminium in this study demonstrates the promising development of high corrosion resistant Mg alloys.

Different thermal degradation mechanisms: Role of aluminum in Ni-rich layered cathode materials

Abstract Despite increasing demands for higher energy density cathode materials, they can be bigger threats unless thermal stability is guaranteed. Herein, the thermal stability of LixNi0.835Co0.15Al0.015O2 (NCA83) and LixNi0.8Co0.15Al0.05O2 (NCA80) is compared by using in-situ transmission electron microscopy. Analysis demonstrates that NCA83 and NCA80 degrade thermally by distinct mechanisms. Al prevents the transition to CoO2-type O1 phase by suppressing O-slab gliding by residual Li. At 67% SOC, in the sub-surface area, thermal degradation of NCA80 is mainly due to reduction of Ni, whereas thermal degradation of NCA83 is a result of concurrent reduction of Ni and Co. The difference indicates that NCA83 has both earlier transition to the rock-salt structure and poorer thermal stability than NCA80. This study presents a protocol to properly evaluate new high energy density cathode materials, and provides important insights into the thermal degradation mechanism of Ni-based layered oxides.

Formation pathway of plate-like ZrB2 particles via the molten salt synthesis method

In this study, the formation mechanism of the plate-like ZrB2 particle via the molten salt synthesis method is investigated. The partial reactions and sequence of reactions were studied using thermo-gravimetric and differential thermal analysis (TG/DTA) on the mixture of starting materials containing Al, KBF4, and K2ZrF6. In order to understand the reactions which take place during the synthesis process, the mixture was heat-treated at the critical temperatures obtained from TG/DTA analysis. The attained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). Results indicated that the formation of AlB2, AlB12, and Al3Zr takes place at a temperature less than 500 °C. Moreover, during the reaction, the formation of KAlF4 besides these products was confirmed by XRD and DTA analyses. The KAlF4 completely melted at the temperature of 575 °C. These particles dissolved in the molten KAlF4 above its melting point, and the reaction between them leads to the formation of the ZrB2 particles. Differences between ZrB2 and intermediate products morphology proposed that the dominant mechanism for ZrB2 formation is solution-precipitation. The role of aluminum is the reduction of starting material at the primary stages and the formation of low melting point salt mixtures. The proposed mechanism of ZrB2 formation was also discussed by the thermodynamics calculation.

Characterization of designed, transparent and conductive Al doped ZnO particles and their utilization in conductive polymer composites

Conducting polymer composites (CPCs) are employed as antistatic coating materials where conductive fillers are dispersed in polymeric matrices. MicNo (=Micron+naNo) polygonal platelets are composed of nano-sized primary particles that exhibit both micron and nano size characteristics. In this study, the role of aluminum (Al) doping on physicochemical characteristics of MicNo-ZnO and the resultant effects on optoelectronic properties were investigated. Morever, the possibility of using such particles in CPC systems for antistatic coatings was also explored. It is shown that Al-doped powders lowers the bulk resistivity of polymers without inducing significant structural changes. For instance, powders with 0.3 mol% Al doping exhibits ≈40 KΩ.cm bulk resistivity which is two orders of magnitude lower than that of undoped sample. Addition of 10 wt% doped powder into epoxy resin reduces the resistivity from ≈6 MΩ.cm to ≈1.7 MΩ.cm. The results show that Al-doped MicNo powders are suitable for utilization in CPCs.

Development of New Wrought Mg Alloys: Improving the Corrosion Resistance by Addition of Alloying Elements

Magnesium (Mg) alloys constitute an attractive structural material for transportation industries, due to their low density and high strength/weight ratio. However, high susceptibility to corrosion of Mg alloys limits their use. Therefore, there is a growing interest for development of new Mg alloys with good mechanical properties and superior corrosion resistance. Production of wrought Mg alloys results in enhancement of mechanical properties, whereas addition of alloying elements may result in improved corrosion behavior. In this study we distinguish the role of aluminum, zinc, tin and calcium additions on the corrosion performance of new wrought Mg alloys. Overall, addition of alloying elements resulted in precipitation of second phase particles with cathodic behavior (relatively to Mg matrix). This enhanced the micro-galvanic effects and the corrosion resistance in short periods of immersion was deteriorated. However, in longer periods of immersion the passive characteristics of the oxide layer played a significant role in improving the alloys' corrosion resistance. The contribution of each element to the oxide layer will be discussed in detail. In general, the quantities of alloying element should be sufficient to stabilize the corrosion products layer; yet as low as possible, in order to reduce the micro-galvanic effects.

A critical role of aluminium on austenite formation in high aluminium added steels

Novel alloys with high aluminium addition have been developed recently for the new concepts of δ-TRIP, δ-QP and some other high-aluminium low-density steels. The aluminium addition dramatically affects the thermodynamics and kinetics of the formation of austenite. In the present study, the effect of aluminium on the initial microstructure of ferrite and pearlite has been investigated. The equilibrium prediction of phase fraction by thermodynamics calculations is in accordance with the measured austenite fraction during isothermal at intercritical temperature range; both results strongly demonstrate a significant influence of aluminium addition on intercritical region. The isothermal transformation of high aluminium steel during intercritical annealing was delayed, which has an instruction for process design of the industrial continuous annealing and galvanization. The austenite formation during heating in intercritical region was also obviously affected by aluminium addition. The transformation kinetics simulation conducted by DICTRA simulation, as well as the experimental results of dilatometry, indicate a delayed austenite transformation during heating process.

Role of aluminum and silicon species in the formation of hard sludge on the secondary side of PWR steam generators: Potential geopolymers contribution

Despite the exhaustive chemical control, modern pressurized water reactors (PWRs) steam generators (SGs) have experienced damage associated with the formation of hard sludge on top of tubesheet. This phenomenon is detrimental because it is linked to tube degradation problems on the secondary side of SGs by corrosion processes, such as outer diameter stress corrosion cracking (ODSCC) enhanced by tube deformation or denting at the top of tubesheet. There is evidence of the contribution of aluminum and silicon species to the binding and adhesion of iron oxides particles in the formation and consolidation of hard sludge during normal operation. In fact, characterization of SG deposit samples mainly constituted by hard sludge determines high concentrations of these species (up to 6.0 ± 0.1 wt% of Al and 2.7 ± 0.1 wt% of Si), together with high microhardness values (above 800 HV) measured at particular locations within collars or hard sludge particles.Taking into account the physicochemical conditions (low temperature and high pH) in the gap between tube and tubesheet of SGs due to the thermal contraction of both materials during transient conditions (cooldown), this work proposes and discusses the possible formation of geopolymers (inorganic aluminosilicate polymers with cement-like mechanical properties formed at low temperatures and high alkaline conditions) during this period. In order to support this proposal, the role played by Si and Al compounds in the formation and consolidation of hard sludge is reviewed, considering information obtained from hard sludge characterization and from experimental studies reported in the literature.

Role of aluminum and HMTA in the hydrothermal synthesis of two-dimensional n-doped ZnO nanosheets

This work reports the study of the processes behind the growth of two-dimensional (2D) n-doped ZnO nanostructures on an AlN layer. We have demonstrated that AlN undergoes a slow dissociation process due to the basic controlled environment promoted by the hexamethylenetetramine (HMTA). The Al(OH)4- ions created inhibits the growth along the c-axis, effectively promoting the fast formation of a planar geometry selectively grown on top of the AlN layer. With the use of this promoting layer and a standard hydrothermal method, a selective area growth is observed with micrometric resolution. In addition, by using several advanced characterization techniques such as, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS/EDX), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL), we observed a resulting doping with aluminum of the ZnO nanostructures, occupying substitutional and interstitial sites, that could lead to new promising applications. These high-quality n-doped ZnO nanosheets (NSs) exhibit strong ultraviolet emission in the 385–405 nm region without broad deep level emission. The piezoelectric nature of these nanostructures has been demonstrated by using piezoresponse atomic force microscope (PFM) and with the support of a piezoelectric test device. Therefore, this low-cost and fast selective-area synthesis of 2D n-doped ZnO NSs can be applicable to other aluminum based materials and paves the way to new promising applications, such as bioelectronic applications, energy generation or self-powered sensing.

The Role of Aluminum in Promoting Ni–Fe–OOH Electrocatalysts for the Oxygen Evolution Reaction

Nickel–iron oxyhydroxide (Ni–Fe–OOH) catalysts have been widely studied for their high activity for the oxygen evolution reaction (OER). Here we demonstrate improved OER activity through incorporat...

Investigating the role of the different metals in hydrotalcite Mg/Al-based adsorbents and their interaction with acidic sorbate species

The role of aluminum in the structure of hydrotalcite-based sorbents was investigated with 27Al-NMR and XPS with respect to the chemisorption mechanism of different sorbate species, such as CO2, H2O and H2S, at elevated temperatures. Sorbent materials with different ratios of Al/Mg were studied in order to elucidate the influence of the material composition on the Al coordination. Two different tetrahedrally and octahedrally coordinated Al species were detected. It was found that their quantitative appearance depends on the ratio of Al/Mg within the sorbent material. A higher Mg content leads to a higher distortion and to the formation of more tetrahedrally coordinated Al with a high chemical shift. Whereas CO2 and H2O adsorption does not seem to influence well-coordinated Al, as observed with NMR, chemisorption of H2S showed a clear interaction with Al leading to the formation of an additional tetrahedrally coordinated site with a high chemical shift. XPS showed that a reversible metal sulfate complex was formed on the sorbent, which was reversible upon exposure to H2O.

Understanding the role of aluminium in determining the surface structure and electrochemical performance of layered cathodes.

The electrochemical properties of layered cathodes can be enhanced by doping with aluminium. However, understanding of the underlying mechanism of Al ion behaviour is deficient, which obstructs its further application. Herein, we adjusted the aluminium content in model LiNi0.85-xCo0.15AlxO2 (LNCA) materials; the sample with the optimum aluminium content (x = 0.05) exhibited excellent electrochemical performance (98.6% capacity retention at 275 mA g-1). Meanwhile, for the samples with excessive aluminium (x = 0.15, 0.30), fast decay of the cycling stability could be observed. Meanwhile, their reversible capacities in the initial cycles were also greatly inferior to the theoretical values. These abnormal phenomena can be attributed to structure cracking and the impedance of Li-ion migration in samples with higher aluminium content. According to the microstructure observations, an unexpected beneficial heterostructure was found to cover the samples with optimum aluminium content, while in the samples with higher aluminium content, this heterostructure was not present. Furthermore, as confirmed by activation barrier calculations, Al ions were found to prefer to thermodynamically occupy the tetrahedral interstices instead of the octahedral sites in Li layers in a high delithiation state. Due to this selective occupancy, proper aluminium content can improve the stability of layered cathodes during cycling. However, excessive aluminium content instead impedes the formation of beneficial surface heterogeneity during synthesis and deeply affects Li-ion migration during cycling. Therefore, the electrochemical performance of the samples with higher aluminium content suffered severe decay. These results and discoveries significantly advance the guidance of microstructural design for next-generation layered cathode materials.

The role of aluminium in C-A-S-H during sulfate attack on concrete

Storage tests with C-A-S-H phases in Na2SO4 solutions (3 and 30 g/L SO4) were carried out to study changes in the C-A-S-H nanostructure during sulfate attack on concrete. Particular attention was paid to the availability of aluminium in C-A-S-H for ettringite formation. Ettringite only formed above the saturation pH of portlandite. The removal of aluminium from C-A-S-H decreased the Al/Si ratio and mean chain length (MCL) of the C-A-S-H phases. No ettringite formed in solutions below the saturation pH of portlandite. Here, decalcification of the C-A-S-H phases resulted in an increase in MCL. The formation of ettringite from aluminium in C-A-S-H exposed to Na2SO4 solutions is controlled by the availability of calcium. Sodium is adsorbed on deprotonated silanol groups in C-A-S-H. At 3 g/L SO4, the SO42− ions are adsorbed with calcium on deprotonated silanol groups, but at 30 g/L SO4, they are also bonded to other sites in C-A-S-H.

The role of aluminum in the formation of macropores, microtubes of silicon and nickel made from porous silicon

Silicon tubes with small dimensions show to be a suitable material for sensors application as well as to other areas of nanotechnology, but its production is not trivial, because of the influence of different formation parameters and the most important of them could be pointed out to the substrate pre-conditioning. In this paper is reported the investigation about the influence of aluminum treatment of crystalline substrates upon the electrical and morphological features of macroporous silicon layers, as well as upon the microtubes yielded by selective corrosion in etchant based in ammonium fluoride solution mixed with nickel ions, as function of the sintering time. The results point out that solely for sample sintered for 4.0 hours nickel microtubes are formed, whereas for other sintered times, silicon microtubes formation are achieved. This fact is strongly linked to the amount of aluminum and oxygen diffused inside the crystalline silicon substrate, which remains even after pores formation. These diffused impurities promote strong chemical modification of the substrate, reason by which its open circuit potential is sharply shifted toward more negative regions. The Tafel plot shows a highest increment of the cathodic current of this sample, which is compatible with the sharp shift of the open circuit potential and enhancement of the exchange anodic current giving rise to the condition for the formation of nickel microtubes through the substitution of silicon atoms by nickel owing to the galvanic displacement effect. The effect of Al-treatment upon the pore's morphology of macroporous layers are shown, as well as the possible mechanism for the formation of nickel microtubes from these macroporous structures are also discussed in this paper.

Anomalous Magnetic and Electrical Properties of Fe2V2−<italic>x</italic>Al<italic>x</italic> (<inline-formula> <tex-math notation="LaTeX">$x = {0-1}$ </tex-math> </inline-formula>) Alloys

Intriguing correlated electronic structure is revealed when vanadium is substituted in place of iron in ferromagnetic DO 3 -Fe 3 Al intermetallic alloy and transforms it into a Fe 2 VAl Heusler alloy with L2 1 crystal structure. This particular composition exhibits nonmagnetic semi-metallic character [1], [2]. Both DFT calculations and experiments revealed the existence of pseudogap or gap ranging up to 0.5 eV. The origin of the gap and the role of hybridization in these alloys is still debated [3]. These studies reveal that the vanadium reduces the moment, yet the role of aluminium in altering the electronic properties is still need to be investigated. Therefore, in the present investigation, we have studied the structural and magnetic properties of Fe 2 V 2-x Al x alloys with x varying from 0 to1 to unravel the role of Al in Fe 2 VAl which is known to be exhibiting the features similar to that of equiatomic FeV. Alloy ingots were synthesized by arc melting the elemental constituents and subsequent annealing at 1273 K for 3 days. From X-Ray Diffraction studies it is observed that x=0 composition (FeV) stabilized in $\sigma -$phase, while a mixed phase (${\sigma }$ + cubic) is obtained for x=0.2. It is observed that as the Al-composition varies from 0.4 to 1 it exhibits a cubic phase. DC magnetic measurements were performed for all samples, which revealed that the magnetic character decreases with Al concentration. The extreme compositions (well ordered) of this series namely, FeV (with $\sigma -$phase) and Fe 2 VAl (L2 1 -phase) are found to be paramagnetic down to lowest temperature. The temperature dependence of magnetization curves shown in Fig.1 for composition x=0.2 suggest ferromagnetic character with Curie temperature (T c ) close to 240 K and for x=0.4 with T c ~130K, while the compositions x=0.8, 1 exhibit nonmagnetic behavior down to 5K (Fig.1). The magnetic isotherms of these compositions exhibit anomalous magnetic character i.e., exhibit higher coercivity at 300K compared to 5K (except for Fe 2 VAl), with lower saturation magnetization. The existence of hysteresis behavior above T c indicates the possibility of the presence of ferromagnetic clusters in intermediate compositions. Analysis of magnetic data suggests that disorder plays a significant role in addition to the composition. To see whether the magnetic anomalies affect the electrical transport, we carried out electrical resistivity measurements in the low temperature range, shown in Fig.2. The electrical resistivity shows a positive temperature coefficient of resistivity (TCR) for x=0 to x=0.8 and the resistivity at temperatures below 250K decreases with Al concentration which indicates the presence of Al improves the metallic nature of these samples. But the sample with highest Al concentration i.e Fe 2 VAl shows negative TCR which also exhibits high values of resistivity compared to other compositions of the series. This kind of behavior can be attributed to band structure formed due to structural disorder in samples, x=0.2, 0.4, 0.8, and pseudo band gap formed in Fe 2 VAl near Fermi level [4], [5]. From above studies, it is quite evident that the material going from metallic state to semi-metallic state with a small variation in Al concentration. The resistivity increased by two orders of magnitude from Fe 2 V 1.2 Al 0.8 Fe 2 VAl, whereas both the samples were paramagnetic down to 5K. An inflection point in resistivity curve near the magnetic transition temperature T c is observed, which suggests a correlation between transport and magnetic properties. These magnetic and electrical transport anomalies show even non-magnetic aluminum plays a significant role in electronic properties and will be discussed in detail.