Quantitative morphological and compositional evaluation of laboratory prepared aluminoborosilicate glass surfaces
Graphical abstract
Introduction
The surface quality has great impact on the performance properties of many novel and emerging technological applications for glasses including those for displays, biomedical applications, microelectronics and advanced optical lithography systems [1], [2]. In some cases the glass surface morphology and overall roughness has become the threshold for the continued development of novel electronics and portable devices [3], [4]. The surface morphology, chemical composition and homogeneity of glass manufacturing products can influence a wide variety of performance related properties including the mechanical strength and chemical durability [5], [6], [7], [8]. Furthermore, smooth, homogeneous and compositionally reproducible glass surfaces are required for mechanistic investigations associated with glass corrosion, chemical tempering, and thin film coating on glasses [9]. For example studies on the dissolution behavior of silicate glasses suggested surface morphology and composition can greatly affect the dissolution or alteration rate of these glasses [10], [11], [12].
A variety of processing methods can be utilized to engineer glass surfaces including mechanical force, chemical and mechanical polishing, and thermal treatment [9], [13], [14]. Each will affect the glass morphology and composition. For example, the annealing of some glass compositions can deplete or enrich the surface in metallic ions due to evaporation and segregation [15]. In the case of chemo-mechanical polishing, chemical reactions between the glass surface and the polishing media polishing can alter the surface composition relative to the bulk glass composition [16], [17], [18], [19]. These changes in surface morphology and chemistry have been shown to effect mechanical, chemical, and aesthetic properties [5], [6], [7], [8]. There are a variety of characterization tools available for the surface compositional and morphological analysis of glass surfaces, each with their own capabilities and limitations. Of particular interest here is X-ray photoelectron spectroscopy (XPS) for quantification of chemical composition and chemical environment and atomic force microscopy (AFM) for surface topographic imaging and quantitative morphological analysis.
XPS is routinely used to determine both the chemical composition and local chemical environment of elements associated with glass surfaces [20], [21]. In particular, under standard operating conditions, as those used in this work, the XPS probes to a depth of approximately 5–10 nm and therefore is a useful probe of the uppermost surface composition and chemistry. Through the empirical derivation of relative sensitivity factors and high resolution peak area analysis absolute quantification of the glass surface composition is achievable [22]. Furthermore through analysis of peak position and shape the chemical environment of the glass forming elements can also be analyzed [23], [24].
AFM is one of the more common techniques in the qualitative and quantitative analysis of glass surface morphology, given its flexibility, relatively low cost, high lateral resolution, and high sensitivity to topographic features on the angstrom to micron scale [25], [26]. Quantitative roughness analysis measured by AFM is often represented by simple statistical parameters, such as average roughness, apparent root-mean-squared roughness (RMS), or peak-to-valley roughness. In these cases, 250,000 data points (512 × 512 pixels per image for example) are expressed by a single number. However, apparent RMS values are problematic since two drastically different topographies can have the same RMS value [27], [28]. This is due to the fact that apparent RMS values are only sensitive to z-axis (vertical) height deviation, not x, y-axis (horizontal) structures. Therefore, such measurements are greatly dependent on the homogeneity of the surface scanned and can be quite problematic, in some cases leading to the difficulty in understanding surface roughness and its spatial distribution homogeneity.
Rather than using the simple above mentioned statistical parameters, surfaces can also be represented by power spectral density (PSD) functions over different spatial frequency regions. PSD is advantageous as it allows the comparison of roughness data measured at different spatial frequencies, offering a convenient representation of the spatial distribution and homogeneity of roughness [25]. This is realized through a 2D fast Fourier transformation algorithm allowing correlation of the z-axis height deviation with the x-, y-axis location data in real and reciprocal space. Furthermore, from the PSD profiles a series of spatially sensitive quantitative roughness parameters can be derived including the fractal dimension, Hurst exponent, correlation length, and equivalent RMS roughness [26].
In this paper we provide a systematic method to prepare smooth glass melt and polished surfaces with surface compositions similar to that of the bulk. Glass surface composition and morphology were quantified using complimentary surface sensitive characterization tools including XPS and AFM. In particular, both vertical and spatial distribution of roughness was investigated using advanced PSD analysis and for the first time, we report spatially sensitive roughness parameters of a variety of glass surfaces as a function of processing.
Section snippets
Glass melting and bulk glass composition analysis
The aluminoborosilicate glass used in this study, referred to as international simple glass (ISG), is a reference waste glass composition developed and utilized by a 6-nation collaborative effort in examining nuclear wasted glass corrosion [29]. The ISG glass used in this study was commercially melted by Mo-Sci Corporation, with melting procedures documented in detail elsewhere and briefly described here [30]. The ISG glasses were batched to yield a nominal weight% composition of 56.2% SiO2,
Bulk glass composition
Table 1 shows the bulk ISG glass elemental composition measured from ICP-AES digestion. The atomic concentration of Na, Ca, Zr, Al, B, Si and O in the bulk ISG glass is 8.0%, 1.6%, 0.4%, 2.4%, 9.4%, 18.0% and 60.1% respectively. Minor deviations, below 0.4%, compared to the ISG bulk glass composition (Na = 7.6%, Ca = 1.7%, Zr = 0.5%, Al = 2.3%, B = 9.6%, Si = 18.0% and O = 60.1%) as reported by Savannah River National Laboratory [30], were observed.
Thermal analysis of bulk ISG glass
Fig. 1 shows the dilatometry/thermal expansion curve and the
Conclusions
In this paper, ISG glass surfaces were prepared through both melting and polishing/etching and the surface composition and morphology were quantified as a function of processing method. In particular, for the first time glass surface morphology as a function of processing method was quantified using PSD analysis, followed by both fractal and ABC model fitting, resulting in a comprehensive description of the spatial distribution of roughness.
All melt surfaces showed a depletion in Na, Ca, and B
Acknowledgements
Funding for this work was provided by the Department of Energy Nuclear Engineering University Program (DOE-NEUP) program under contract number DE-AC0705-ID14517. The authors would like to thank Vince Bojan of The Pennsylvania State University Materials Characterization Laboratory for XPS analyses. We acknowledge Melanie Saffer of The Pennsylvania State University Laboratory for Isotopes and Metals in the Environment for bulk ICP analysis.
References (52)
- et al.
Mechanical strength improvement of a soda-lime-silica glass by thermal treatment under flowing gas
J. Euro. Cer. Soc.
(2004) - et al.
The role of surface oxide composition on the fatigue strength of metallic glass wire
Appl. Surf. Sci.
(2014) - et al.
Chemical durability and microstructural analysis of glasses soaked in water and in biological fluids
Cer. Intl.
(2009) - et al.
Effect of the glass composition on the chemical durability of zinc-phosphate-based glasses in aqueous solutions
J. Phys. and Chem. of Solids.
(2013) - et al.
Ultraprecision Grinding of Optical Glasses to Produce Super-Smooth Surfaces
CIRP. Ann.-Manuf. Techn.
(1993) Chemical Processes in Glass Polishing
J. Non-cryst. Solids
(1990)Surface-Chemistry of Optical-Glasses
J. Non-Cryst. Solids
(1991)Zinc Phosphate-Glass Surfaces Studied by XPS
J. Non-Cryst. Solids
(1993)- et al.
XPS Study of Leached Glass Surfaces
J. Non-Cryst. Solids
(1990) An XPS study of oxygen bonding in zinc phosphate and zinc borophosphate glasses
J. Non-Cryst. Solids
(1996)
XPS Measurements and Structural Aspects of Silicate and Phosphate-Glasses
J. Non-Cryst. Solids
Characterization of microroughness parameters in gadolinium oxide thin films: A study based on extended power spectral density analyses
Appl. Surf. Sci.
Preparation of high strength foam glass-ceramics from waste cathode ray tube
Mater. Lett.
Investigation of crystallization kinetic of SrO-La2O3-Al2O3-B2O3-SiO2 glass and its suitability for SOFC sealant
Intl. J. Hydrogen Ener.
Mechanism of the etching rate change of aluminosilicate glass in HF acid with micro-indentation
Appl. Surf. Sci.
Network connectivity in aluminoborosilicate glasses: A high-resolution B-11, Al-27 and O-17 NMR study
J. Non-Cryst. Solids
Solid-state NMR examination of alteration layers on nuclear waste glasses
J. Non-Cryst. Solids
The effect of HF/NH4F etching on the morphology of surface fractures on fused silica
J. Non-Cryst. Solids
Effect of nucleation temperatures and time on crystallization behavior and properties of Li2O-Al2O3-SiO2 glasses
Mater. Chem. Phys.
The origin of the exothermic peak in the thermal decomposition of basic magnesium carbonate
Thermochimica Acta
Wetting and surface tension of bismate glass melt
Thermochimica Acta
Nanoscale roughness of oxide glass surfaces
J. Non-Cryst. Solids
Surface Chemistry and Microstructure of Flat-Panel Display Substrates
SID 91 Dig.
Investigation of borophosphosilicate glass roughness and planarization with the atomic force microscope technique
Thin Solid Films
Critical processes for ultrathin gate oxide integrity: Physics and Chemistry of SiO2 and the Si-SiO2 Interface
Electrochem. Soc.
Si/SiO2, Interface States and Neutral Oxide Traps Induced by Surface Microroughness
J. Appl. Phys.
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