Al Fraction Research Articles

Aluminium (Al) fractionation and speciation; getting closer to describing the factors influencing Al3+ in water impacted by acid mine drainage

Acid mine drainage (AMD) severely impacts the water chemistry of a receiving resource, changing the occurrence, speciation and toxicity of metals such as Aluminium (Al). The toxicity of Al is determined by its speciation represented by the labile monomer Al fraction or Al3+. The purpose of the study was to combine fractionation and Visual MINTEQ speciation to calculate the effect of AMD altered water chemistry on Al speciation and Al3+ concentration. Water in rivers impacted by AMD presented with monomeric Al (Almon) concentrations between 0.35 and 15.37mgL−1 which existed almost exclusively in the toxic labile form (98%). For the reference site, Almon was less than 2% (10μgL−1), suggesting significantly lower Al toxicity. Principal component analysis plots illustrated that labile Al was directly related to the total Al and iron concentrations and strongly influenced by parameters such as pH, electrical conductivity, sulphate and dissolved organic carbon. Visual MINTEQ modelling was used to determine the primary Al species distribution. The dominant form of Al in AMD impacted water was AlSO4+, which increased proportionally with the sulphate and Al3+ concentration. Heavily impacted areas, presented with an average of 1mgmL−1 Al3+, which poses a potential human health risk. A novel centrifugal ultrafiltration method was investigated as an alternative to determining Almon to simplify the speciation of Al. Monomeric and centrifugal ultrafiltrated (<10kD) Al fractions were significantly similar (p=0.74), suggesting that ultrafiltration may present a time, energy and cost saving alternative to organic extraction of Almon.

Characterization of soils in terms of pedological variability under different physiography of Damodar command area (part), West Bengal, India

AbstractFive representative soil profiles occurring on four different physiography under subtropical environment of Damodar command area, India, were studied for soil pedological variability. Two way approaches were taken to evaluate the extent of profile development. Firstly different extractants were used to determine various forms of Fe and Al and their different ratios. Average contents of Fe and Al, extracted by different extracting reagents were found to be in descending order, as follows: Aldith > Aloxa > Alpyr and Fedith > Feoxa > Fepyr. Analysis of pyrophosphate (pyr), oxalate (oxa), and dithionate (dith) extractable Fe and Al fractions indicated that with increasing soil age, the content of crystalline Fe and Al oxides increased at the expense of the poorly crystalline forms. The mean content of amorphous Fe and Al, crystalline Fe and Al, and their ratios estimated the degree of soil development. In the second part, elemental analysis was done, silica to sesquioxide ratio as well as ratio of alk...

Comprehensive study of the electronic and optical behavior of highly degenerate p-type Mg-doped GaN and AlGaN

The bulk and 2-dimensional (2D) electrical transport properties of heavily Mg-doped p-type GaN films grown on AlN buffer layers by Metal Modulated Epitaxy are explored. Distinctions are made between three primary p-type conduction mechanisms: traditional valence band conduction, impurity band conduction, and 2D conduction within a 2D hole gas at a hetero-interface. The bulk and 2D contributions to the overall carrier transport are identified and the relative contributions are found to vary strongly with growth conditions. Films grown with III/V ratio less than 1.5 exhibit high hole concentrations exceeding 2 × 1019 cm−3 with effective acceptor activation energies of 51 meV. Films with III/V ratios greater than 1.5 exhibit lower overall hole concentrations and significant contributions from 2D transport at the hetero-interface. Films grown with III/V ratio of 1.2 and Mg concentrations exceeding 2 × 1020 cm−3 show no detectable inversion domains or Mg precipitation. Highly Mg-doped p-GaN and p-AlGaN with Al fractions up to 27% similarly exhibit hole concentrations exceeding 2 × 1019 cm−3. The p-GaN and p-Al0.11Ga0.89N films show broad ultraviolet (UV) photoluminescence peaks, which intercept the valence band, supporting the presence of a Mg acceptor band. Finally, a multi-quantum-well light-emitting diode (LED) and p-i-n diode are grown, both of which demonstrate rectifying behavior with turn-on voltages of 3–3.5 V and series resistances of 6–10 Ω without the need for any post-metallization annealing. The LED exhibits violet-blue luminescence at 425 nm, while the p-i-n diode shows UV luminescence at 381 nm, and both devices still show substantial light emission even when submerged in liquid nitrogen at 77 K.

Long‐Term Fertilization Practices Alter Aluminum Fractions and Coordinate State in Soil Colloids

Understanding how fertilization practices affect Al fractions is important for the alleviation of soil acidification and the sequestration of soil organic C (SOC). Two selective extraction methods, high‐resolution 27Al nuclear magnetic resonance (NMR) spectroscopy and Fourier‐transform infrared spectroscopy (FTIR), were used to assess the transformation of Al fractions in Ferralic Cambisol soils under long‐term (22‐yr) treatment with chemical and/or organic fertilizers. The results showed that Al fractions were significantly (P &lt; 0.05) altered by long‐term fertilization. Compared with chemical fertilization (N and N–P–K), organic fertilization (manure alone and N–P–K with manure) significantly (P &lt; 0.05) increased amorphous Al and decreased exchangeable Al, while the addition of lime (N with lime and N–P–K with lime) significantly (P &lt; 0.05) increased weakly organically bound Al and decreased exchangeable Al. Amorphous Al was significantly positively correlated with soil C (P &lt; 0.01), indicating that amorphous Al could enhance soil C sequestration. In contrast, exchangeable Al was significantly negatively correlated with soil pH (P &lt; 0.01), indicating that reducing the concentration of exchangeable Al could alleviate soil acidification. The 27Al NMR and FTIR spectroscopy results of soil colloids further confirmed the presence of amorphous Al as allophane and imogolite in soil colloids under no‐fertilization and organic‐fertilization treatments but not under chemical fertilization, suggesting that the enhancement of soil nanominerals by organic fertilization may be another new mechanism for alleviating soil acidification. Our results provide novel insight into how Al fractions and their coordinate states under long‐term fertilization enhance soil C sequestration while alleviating soil acidification.

Correlated room temperature ferromagnetism and photoluminescence in Al-doped SnO2 nanoparticles

The correlated room temperature ferromagnetism and photoluminescence were investigated in Al-doped SnO2 nanoparticles (about 50 nm) synthesized by the sol-gel method. X-ray diffraction and selected area electron diffraction results show that the Sn1−x Al x O2 samples possess typical rutile structure and have no other impurity phases with Al fractions of up to 8 at.%. The optical bandgap energies decrease, while the Urbach energies increase with Al concentration. The ferromagnetic signature was found to be significantly enhanced after Al doping, with the saturation magnetization reaching a maximum of 7.3 × 10−3 emu/g in Sn0.92Al0.08O2 sample. The photoluminescence studies clearly indicated the presence of a large concentration of singly ionized oxygen vacancies in the pure and Al-doped SnO2 nanoparticles. An interesting correlation between the saturation magnetization and green–yellow luminescence intensity with the increase of Al doping has suggested that the observed ferromagnetic ordering of the Sn1−x Al x O2 nanoparticles is related to the singly ionized oxygen vacancies.

Impact of short-range scattering on the metallic transport of strongly correlated two-dimensional holes in GaAs quantum wells

Understanding the non-monotonic behavior in the temperature dependent resistance, R(T), of strongly correlated two-dimensional (2D) carriers in clean semiconductors has been a central issue in the studies of 2D metallic states and metal-insulator-transitions. We have studied the transport of high mobility 2D holes in 20nm wide GaAs quantum wells (QWs) with varying short-range disorder strength by changing the Al fraction x in the Al_xGa_{1-x}As barrier. Via varying the short range interface roughness and alloy scattering, it is observed that increasing x suppresses both the strength and characteristic temperature scale of the 2D metallicity, pointing to the distinct role of short-range versus long-range disorder in the 2D metallic transport in this correlated 2D hole system with interaction parameter r_s~ 20.

Aluminum and nutrient interplay across an age-chronosequence of tea plantations within a hilly red soil farm of subtropical China

Aluminum (Al) and nutrients are key factors to influence tea (Camellia sinensis L.) productivity and quality, while how they interplay in tea plantations under the pressure of global change and increasing fertilization is little studied. In this study, we selected the tea plantations along an age-chronosequence to study Al fractions using a sequential extraction procedure, and nutrient concentrations in topsoil and subsoil and various plant organs. Our results indicated that Al levels and nutrient concentrations in soils and plants generally increased with planting year (P < 0.05), and soil Al bioavailability was positively correlated with Al concentrations in most plant organs. Significant negative relations among pH and most extractable Al fractions in both soil layers suggested that decreased pH would directly alter soil-plant Al cycling due to exogenous nitrogen (N) fertilizer and atmospheric acid deposition. Topsoil total phosphorus (P) was positively correlated with most Al fractions, and root P was positively correlated with root Al concentration, both of which indicate that P and Al were synchronously absorbed by roots in acid tea soils. In addition, topsoil organic carbon was positively correlated with both active and inert Al fractions, indicating that above-ground organic litters would be the main source of elevated Al levels in older tea plantations. Clearly, Al enrichment in tea leaves with increasing planting year needs to be considered under management practices with heavy N and P fertilizers and increasing atmospheric acid deposition in subtropical China.

Effect of layer thickness on the high temperature mechanical properties of Al/SiC nanolaminates

Composite laminates on the nanoscale have shown superior hardness and toughness, but little is known about their high temperature behavior. The mechanical properties (elastic modulus and hardness) were measured as a function of temperature by means of nanoindentation in Al/SiC nanolaminates, a model metal–ceramic nanolaminate fabricated by physical vapor deposition. The influence of the Al and SiC volume fraction and layer thicknesses was determined between room temperature and 150°C and, the deformation modes were analyzed by transmission electron microscopy, using a focused ion beam to prepare cross-sections through selected indents. It was found that ambient temperature deformation was controlled by the plastic flow of the Al layers, constrained by the SiC, and the elastic bending of the SiC layers. The reduction in hardness with temperature showed evidence of the development of interface-mediated deformation mechanisms, which led to a clear influence of layer thickness on the hardness.

Influence of Al fraction on photoemission performance of AlGaN photocathode

To research the photoemission performance of a transmission-mode Al(1-x)Ga(x)N photocathode, Al0.24Ga0.76N and GaN photocathodes with the same structure were activated, their spectral responses were measured using a multi-information measurement system at room temperature, and the photocathode parameters were obtained by fitting quantum efficiency curves. The results showed that both the reflective-mode and transmission-mode spectral responses of the AlGaN photocathode were lower than those of the GaN photocathode. Compared with the GaN photocathode, the short-wavelength spectral response of the Al0.24Ga0.76N photocathode was less seriously affected by lattice defects between the buffer and emission layers. The Al atom at the AlGaN photocathode surface could affect the optimal Cs adsorption position, which mainly affects the surface electron escape probability of the photocathode.

Speciation study of aluminium in beverages by Competitive Ligand Exchange–Adsorptive Stripping Voltammetry

Competitive Ligand Exchange-Adsorptive Stripping Voltammetry (CLE-AdSV) was used for determining the speciation of aluminium in commonly consumed beverages (water, tea, infusion, coffee, orange juice, tomato juice, beer and red wine). Aluminium determination involves the adsorption of Al-complexes with the ligand cupferron onto a hanging mercury drop electrode. All samples were studied at pH 6.5 with an accumulation step at -0.60 V (all potential values in the paper are given versus the Ag/AgCl, [KCl]=3 M reference electrode) during 60 s, and a final cupferron concentration of 4 × 10(-4)M. These conditions were used to establish (i) the concentration of electro-labile aluminium, (ii) the range of ligand concentrations and (iii) the conditional stability constants of beverage samples using titration procedures. The results based on Ruzic plots were compared to computer simulation with Visual MINTEQ. This comparison suggests that labile monomeric Al-forms and soluble organic complexes of low molecular weight can be quantified by the CLE-AdSV procedure. Overall the relative uncertainties on the determination of the electro-active Al fraction and the complexing parameters, i.e., concentration and conditional stability constant of natural ligands in the samples, are less than 15%. Thanks to these results, information on Al bioavailability in beverages was collected and discussed. This study also illustrates the value of computer simulations when complex, time-consuming voltammetric techniques are applied.

NAA-SLR and ICP-AES Application in the Assessment of Mass Fraction of 19 Chemical Elements in Pediatric and Young Adult Prostate Glands

The effect of age on the mass fraction of 19 chemical elements in the intact prostate of 50 apparently healthy 0-30-year-old males was investigated by neutron activation analysis with high-resolution spectrometry of short-lived radionuclides and inductively coupled plasma atomic emission spectrometry. Mean values (M ± standard error of the mean) for mass fraction (in milligrams per kilogram, on dry weight basis) of chemical elements were as follows: Al, 77 ± 17; B, 1.31 ± 0.29; Ba, 4.0 ± 1.2; Br, 37.7 ± 4.3; Ca, 1,536 ± 189; Cl, 13,414 ± 949; Cu, 12.3 ± 2.1; Fe, 132 ± 11; K, 11,547 ± 468; Li, 0.064 ± 0.009; Mg, 922 ± 89; Mn, 1.88 ± 0.16; Na, 9,834 ± 411; P, 6,741 ± 335; S, 8,034 ± 251; Si, 199 ± 34; Sr, 1.40 ± 0.19; and Zn, 277 ± 33. The upper limit of mean mass fraction of V was ≤0.24. This work revealed that there is significant tendency for the mass fractions of Ca, K, Mg, and Zn in the prostate tissue of healthy individuals to increase with age from the time of birth up to 30 years. It means that Ca, K, Mg, and Zn mass fractions in prostate tissue are the androgen-dependent parameters. Our finding of a positive correlation between the prostatic Zn and Ca, K, Mg, P, and S mass fractions indicates that there is a special relationship of Zn with some main electrolytes (Ca, K, and Mg) and with P- and S-containing compounds in the prostate. It was shown also that high levels of Al, B, Ba, Br, Cl, Li, Na, and Sr mass fraction in prostate tissue do not indicate a direct involvement of these elements in the reproductive function of the prostate.

Measuring the composition of AlGaN layers in GaN based structures grown on 150 mm Si substrates using (2 0 5) reciprocal space maps

A critical element for the successful growth of GaN device layers on Si is accurate control of the AlGaN buffer layers used to manage strain. Here we present a method for measuring the composition of the AlGaN buffer layers in device structures which makes use of a one-dimensional x-ray detector to provide efficient measurement of a reciprocal space map which covers the full compositional range from AlN to GaN. Combining this with a suitable x-ray reflection with low strain sensitivity it is possible to accurately determine the Al fraction of the buffer layers independent of their relaxation state.

Direct Determination of Potentially Toxic Elements in Rice by SS-GF AAS: Development of Methods and Applications

The development of methods for direct determinations of Al, Cd, and Pb in rice by SS-GF AAS is presented. Heating program optimization associated with the use of an adequate chemical modifier containing Pd + Mg allowed direct analysis against aqueous calibrations. The obtained LOD values were 114.0, 3.0, and 16.0 μg kg⁻¹ for Al, Cd, and Pb, respectively. Important parameters associated with a solid sampling analysis were investigated, such as minimum and maximum sample mass size and analyte segregation. Seventeen rice samples available in São Paulo City were analyzed, and all of them presented analyte mass fractions less than the maximum allowed by legislation. The influences of rice washing and the cooking procedure were also investigated. The washing procedure diminished the Al and Pb total mass fractions, indicating an exogenous grain contamination. The cooking procedure diminished the Cd total mass fraction. Rice cooking using an aluminum container did not cause a significant increase in the Al mass fraction in the rice, indicating no translocation of this element from container to food. In general, coarse rice presented higher levels of Al when compared to polished or parabolized rice.

Oxygen vacancy enhanced room temperature magnetism in Al-doped MgO nanoparticles

We have measured the room temperature magnetization in Al-substituted magnesium oxide, Mg(Al)O nanoparticles with Al fractions of up to 5 at. %. All samples, including undoped MgO nanoparticles, exhibit weak room temperature ferromagnetism, with the saturation magnetization reaching a maximum of 0.023 emu/g at 2 at. % of Al. X-ray photoelectron spectroscopy identifies the presence of oxygen vacancies in both doped and undoped MgO nanoparticles, with the vacancy concentration increasing upon vacuum annealing of Mg(Al)O, resulting in two-fold enhancement of the saturation magnetization for 2 at. % Al-doped MgO. Our results suggest that the oxygen vacancies are largely responsible for the weak room temperature ferromagnetism in MgO.

Phase transitions and magnetocaloric effect of Ni1.7Co0.3Mn1+xAl1−x Heusler alloys

Structural and magnetic phase transitions of Ni1.7Co0.3Mn1+xAl1−x (x=0.22–0.3) alloys were characterized to evaluate the magnetocaloric effect (MCE) of the alloys. The Curie temperature remained at ∼360K regardless of the composition whereas the Al fraction determined the temperature and extent of the martensitic transition. The alloy with x=0.26 had the highest peak magnetic entropy change (|ΔSM|pk) of 2.1Jkg−1K−1 and refrigerant capacity (RC) of 49Jkg−1 with ΔH=10kOe, originating from the martensitic transformation. The |ΔSM|pk and RC values were comparable to those of other Ni–Mn–X alloys. The alloy with x=0.3 may also serve as a magnetic refrigerant near room temperature in spite of its relatively low |ΔSM|pk and RC values. Our result suggests that it should be possible to fine-tune the composition of the quaternary NiCoMnAl alloy to attain optimal magnetocaloric effect near room temperature.

Use of Neutron Activation Analysis and Inductively Coupled Plasma Mass Spectrometry for the Determination of Trace Elements in Pediatric and Young Adult Prostate

The questions about the androgen control and the involvement of trace elements in prostatic reproductive function still remain unanswered. One valuable way to elucidate the situation is to compare the values for the prostatic mass fractions of trace elements in pre-and post-pubertal boys. The effect of age on the mass fraction of 54 trace elements in intact prostate of 50 apparently healthy 0-30 years old males was investigated by neutron activation analysis and inductively coupled plasma mass spectrometry. Mean values (M ± SΕΜ) for mass fraction (milligram per kilogram, on dry-weight basis) of trace elements were: Ag 0.062 ± 0.008, Al 80 ± 18, Au 0.0092 ± 0.0024, B 5.9 ± 3.5, Be 0.0034 ± 0.0009, Bi 0.018 ± 0.010, Br 26 ± 3, Cd 0.26 ± 0.05, Ce 0.049 ± 0.012, Co 0.035 ± 0.004, Cr 0.49 ± 0.07, Cs 0.036 ± 0.005, Dy 0.0072 ± 0.0018, Er 0.0040 ± 0.0011, Fe 100 ± 10, Gd 0.0065 ± 0.0018, Hg 0.031 ± 0.004, Ho 0.0013 ± 0.0004, La 0.034 ± 0.007, Li 0.064 ± 0.009, Mn 1.69 ± 0.15, Mo 0.54 ± 0.13, Nb 0.013 ± 0.004, Nd 0.025 ± 0.006, Ni 4.1 ± 0.6, Pb 1.3 ± 0.2, Pr 0.0058 ± 0.0015, Rb 14.5 ± 0.8, Sb 0.051 ± 0.006, Sc 0.013 ± 0.002, Se 0.54 ± 0.03, Sm 0.0055 ± 0.0015, Sn 0.22 ± 0.05, Tb 0.0012 ± 0.0004, Th 0.0076 ± 0.0020, Ti 2.8 ± 0.5, Tl 0.0032 ± 0.0009, Tm 0.00064 ± 0.00017, U 0.0025 ± 0.0004, Y 0.036 ± 0.010, Yb 0.0037 ± 0.0012, Zn 281 ± 32, and Zr 0.16 ± 0.04. The upper limit of mean mass fraction of As, Eu, Ga, Hf, Ir, Lu, Pd, Pt, Re, and Ta were: As ≤ 0.069, Eu ≤ 0.0012, Ga ≤ 0.071, Hf ≤ 0.049, Ir ≤ 0.00054, Lu ≤ 0.00063, Pd ≤ 0.014, Pt ≤ 0.0029, Re ≤ 0.0048, and Ta ≤ 0.010. This work revealed that there is a significant tendency for the mass fractions of Cd, Se and Zn in the prostate tissue of healthy individuals to increase with age from the time of birth up to 30 years. It was also shown that high levels of Al, Au, B, Br, Cr, Ga, Li, and Ni mass fraction in prostate tissue do not indicate a direct involvement of these elements in the reproductive function of prostate.

The distribution of inherent phosphorus in fifteen water treatment residues from South Africa

Water treatment residues (WTR), the by-products of the production of potable water, are chemically benign, inorganic materials which are suitable for disposal by land application, though they are frequently reported to have high phosphorus (P) sorption capacities. An understanding of the distribution of inherent P in WTR is, however, required, if sorption-desorption processes are to be correctly interpreted. The aim of this investigation was to characterise the chemical properties relevant to P-sorption/desorption processes of 15 South African WTR and to determine the inherent distribution of P within the WTR using a chemical fractionation procedure. The pH, exchangeable Ca and organic carbon content ranged from 4.77 to 8.37, 238 to 8 980 mg·kg-1 and 0.50 to 11.6 g·100 g-1, respectively. Dithionate, oxalate and pyrophosphate extractable Al fractions ranged from 741 to 96 375, 1 980 to 82 947 and 130 to 37 200 mg·kg-1, respectively, and dithionate, oxalate and pyrophosphate extractable Fe ranged from 441 to 15 288, 3 865 to 140 569 and 230 to 90 000 mg·kg-1, respectively. Mechanisms of P-retention are residue specific, being dependent on the chemical properties of the WTR. Elevated Ca and amorphous Al and Fe concentrations did, nevertheless, suggest that all residues had the capacity to adsorb high amounts of P and to retain this P in forms unavailable for plant uptake.

Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): Effect of OH/Al, Si/Al molar ratios and initial pH

An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly-aluminum-silicate-chloride (PASiC) in terms of the residual Al fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual Al ratio of the composite PASiC coagulant. The main residual Al sources were the Al fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00–7.00, while the concentrations of various residual Al species and the residual Al ratio of PASiC were minimal at an initial pH range of 7.00–8.00. Under the conditions of OH/Al molar ratio = 2.00 and Si/Al molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual Al concentrations. The Al fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended (filterable) Al fraction was the dominant species, and organic-bound or organo-Al complex Al was considered to be the major species of dissolved Al in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric Al species dominated the dissolved monomeric Al fraction.

Relationship between residual Al species, floc operational parameters and coagulation performance during reservoir water treatment by PAC–PDMDAAC

This study investigated the relationship between removal efficiency, floc operational parameters and residual Al species when polyaluminum chloride–polydiallyl dimethyl ammonium-chloride (PAC–PDMDAAC) was applied in coagulation of a reservoir water. Various residual Al fractions (total Al, dissolved Al, dissolved monomeric Al, dissolved organically-bound Al and dissolved organic monomeric Al, suspended/particulate Al) were separated and measured in purified water samples. The fundamental floc operational parameters were characterized via floc size, growth rate, and strength factor in this study. Turbidity and organic matter removal were also determined as supporting data. Experimental results demonstrated that the mass ratio of Al to PDMDAAC (MR) and solution pH manifested a significant influence on residual Al speciation distribution. Residual Al content and floc operational parameters exhibited a linear correlation. In addition, moderate floc size, strength factor, growth rate and removal efficiency were favorable to the reduction of residual Al concentration for one coagulant under various pH conditions. For different coagulation system under the same pH condition, the higher the values of floc operational parameters and removal performance, the lower the residual Al content. The Al speciation was altered before and after coagulation. A majority of total Al in treated water was in the dissolved form. In dissolved Al form, the monomeric Al and organically bound Al were presented at a higher proportion under conditions of 4<pH<6 and pH>7, respectively.

Microstructure analysis of novel ternary NiSi2−xAlx silicide layers on Si(001) formed by solid-state reaction

Phase formation due to annealing of Al/Ni (z:1) films on Si was investigated on the nanometer scale as a function of Al content and annealing temperature. An addition of Al to the Ni-Si system followed by annealing at 500 °C results in the formation of different Ni-Al-Si compounds depending on the Al content. Furthermore, a reduction of disilicide formation temperature from 700 °C down to 500 °C was observed in the presence of Al. In particular, grains of ternary NiSi2−xAlx were observed at the NiSi/Si interface after the 500 °C annealing even for a small Al amount of z = 0.1. A 900 °C annealing leads to the formation of continuous NiSi2−xAlx layers. The interfacial roughness of the layers strongly depends on the Al content and reaches its minimum for an Al fraction (z) ranging from 0.2 to 0.4. Using results of transmission electron microscopy analysis, a model describing the formation of ternary NiSi2−xAlx is proposed.