A combinatorial method to screen large numbers of dopants that affect the nucleation of yttrium-aluminum garnet was developed. The method involves heat-treatment of electron-transparent sol-derived thin films on TEM grids, and counting the number and size of nuclei by TEM. Advantages and limitations of the technique are discussed. Preliminary results are presented.

It is proposed to supplement a phase diagram by a structural diagram, which represents the mass portions of phases, conglomerates or their elements upon the system concentration at fixed temperature. Methods of structural diagrams and concentration maps construction are considered. Concentration map is a projection of structural diagram. It marks a concentration triangle by the lines of constant mass portions of a phase or its elements.

High throughput screening methods for evaluating oxygen and moisture barriers are described. The screening methods are based on the change in a certain optical property, such as absorbance or fluorescence, due to a chemical reaction with oxygen gas or water vapor. The results of these measurements for several cases are presented and their advantages and disadvantages are discussed.

In this paper, we demonstrate the use of thermal probe method that is capable of mapping Seebeck coefficient, thermal conductivity and contact resistance on a micrometer scale. We show the successful screening example on pseudo binary (Bi1−xSbx)2Te3 (0.5<x<1) bulk composition-spread sample prepared by conventional powder metallurgy process. Another demonstration is a novel attempt to combine the combinatorial PLD and the thermal probe method. A pseudo ternary diagram of nickel-copper-manganese oxides fabricated on Nb doped STO substrate was used for the screening. The mapping of electrical resistance over the ternary diagram yields a lot of information, which is essential for materials researches on complex, multi-composition systems.

Multilayer transparent conducting oxide (TCO) structures consisting of alternating layers of tin oxide (SnO2) and cadmium oxide (CdO) pairs was studied. A low-pressure metalorganic chemical vapor deposition with a linear combinatorial approach was used to fabricate the libraries. Three libraries were studied with the pair thickness range covered from 500 nm to 4 nm. For pairs thicker than 150 nm, the material properties of the multilayer simply show a combination of CdO and SnO2 characteristics. When pair thinner than 70 nm, the interface effect started emerging. As pairs became thinner than 20 nm, the new compound phase was formed.

The relative thermal stability of 44 colorants of interest to GE Plastics as polymer colorants was determined. The effects of common (non-colorant) additives on the thermal stability in a polymer matrix were also determined. The measurements were carried out by reflectance spectrometry on thin films of polymers that had been subjected to heating cycles. The change in the visible spectrum was used as an indicator of thermal stability. This paper discusses the method and overall results for the experiments.

A combinatorial approach was employed to ion beam synthesis and optical analysis of buried II-VI compound CdSe semiconductor nanocrystals. Typically standard ion implantation setups are designed in a way to create a laterally homogenous dose distribution of the implanted ion species. In order to achieve intentional lateral variations of the implanted doses a special implanter endstation was constructed. Computer controlled apertures in front of the wafer cover up in succession parts of a 4 in. wafer, so that a lateral pattern of distinct dose combinations of the implanted elements Cd and Se was generated. The obtained materials library consists of 1:1 stoichiometric, but also off-stoichiometric dose ratios. After implantation the wafers passed through a rapid thermal heat treatment, where the implanted material forms buried semiconductor nanocrystals. Photoluminescence spectra of the elements of the materials library were screened in rapid succession in an optical cryostat into which the whole wafer was mounted and cooled down. The obtained spectra were compared and key-parameters determined which control the photoluminescence properties. In this contribution will be shown, that slight variations of the dose ratio significantly alter the optical properties and that new efficient photoluminescent materials and processing parameters can be found. In this way, also other complex interdependencies of physical and chemical parameters in the field of multiple element ion beam implantation might be efficiently investigated.

Ternary libraries are prepared by codeposition of Cr, Fe, and Ni on single-crystal Si and Al2O3 (sapphire) substrates at ∼100°C. The varying proximity to the three metal sources produces a spread of compositions in the films, which are analyzed both as-deposited and after annealing in vacuum for 2 h at 500°C. Structural maps are produced using synchrotron radiation and simultaneous detection of 2D diffraction patterns and x-ray fluorescence spectra. Four phases are identified in the as-deposited films. Three phases occur in equilibrium: bcc (α), fcc (γ), and intermetallic (σ). The fourth phase does not correspond to any equilibrium phase in the Cr-Fe-Ni system; it is tentatively identified as isomorphic to the α-Mn (A12) structure. After annealing, the nonequilibrium phase is no longer observed, but the occurrence of the three equilibrium phases is still far from the equilibrium phase boundaries. The particle size measured by x rays is small (9–15 nm), suggesting that higher annealing temperatures are required for the growth of equilibrium phases.

We developed a recursive image charge approach for quantitative characterizations of dielectric thin films using the scanning tip microwave near-field microscope. With this method, frequency shift of the microscope as functions of the dielectric constant and the thickness of a film can be effectively computed in a recursive way. We believe that this approach can promote the high-throughput characterization of the dielectric libraries.

We discuss methods leading to the fabrication of orthogonal substrates comprising surface-anchored polymer brushes, in which the polymer brush grafting density and molecular weight vary independently in two mutually perpendicular directions. We demonstrate that these orthogonal polymer substrates can be used as intelligent combinatorial platforms that facilitate the spatial distribution of nanoparticles and allow screening of protein adsorption on surfaces.

Rapid prototyping of microfluidic handling devices has gained popularity due to the ability to quickly test and modify new design features several times in one day. At the NIST Combinatorial Methods Center (NCMC), we have modified common microfluidic fabrication techniques to extend their use to organic fluids. Ultraviolet (UV) curable adhesives were used to create molded resins with increased solvent resistance. This has allowed the preparation of new types of combinatorial libraries and development of new measurement methods to complement the small sample sizes of these libraries. Most importantly, it can be used to tie together multiple stages of the formulation process, from the synthesis of polymers to the measurement of complex-fluid properties, in small and inexpensive platforms. Our first demonstrations of this technology are in the areas of emulsions and polymer blends. Measurement techniques include light and x-ray scattering and rheology. Milli-fluidic handling and measurements will increase the dimensions of parameter space that are available to accurate and systematic study of polymer solutions. These capabilities will also enable the generation of new information in the field of polymer formulations, which is presently dominated by empirical knowledge.

A combinatorial method for the development of organic clear coatings for plastic substrates has been developed. The combinatorial process or combinatorial factory has a throughput on the order of 100–200 coatings per day and possesses all of the aspects of a conventional combinatorial process such as automated sample preparation, miniaturized samples configured in an array format, high throughput screening of the properties of interest, and computer software developed for data management, storage, and analysis. The combinatorial factory greatly enhanced the rate of organic clear coat development.

We propose a new concept and method for high throughput screening of flux materials used in the bulk single crystal growth. The concept of our tri-phase epitaxy has been generalized as the flux-mediated epitaxy with the aid of quick optimization of flux materials in the combinatorial thin-film technology. Here, we report on the successful discovery of a new flux composition of Bi-Ti-Cu-O for the growth of high-quality Bi4Ti3O12 bulk crystal and thin film.

A new general approach for rapid performance screening of polymer compositions is provided. Multiple compositions are generated as one-dimensional libraries in a micro-extruder with step or gradient composition changes in < 1 min. To accelerate testing, an environmental stress is applied to only local regions, followed by high-sensitivity spatially resolved characterization. Applying the methodology to weathering of arrays of polymeric compositions provided a 20X faster ranking of polymer/UV absorber compositions that was equivalent to traditional weathering methods.

Materiomics is a new approach combining combinatorial surveys and precise structure analyses in order to develop new functional materials efficiently. In this paper, we show the first stage of materiomics applied to metal/metal oxide catalysts. The catalytic activities of various metal/metal oxide catalysts for hydrogen production have been examined by a combinatorial method, and TEM observations have been performed for the selected catalysts from the libraries in order to estimate the structures in the combinatorial surveys. A Pd/MnO2 catalyst shows the high activity for the water gas shift reaction, where thin Pd oxide layers about 1–2nm thickness are formed on the flat MnO2 surface. However, Pd oxide layers are reduced and metallic Pd particles 2–3nm in diameter with narrow size distribution are formed after hydrogen reduction. The structure of manganese oxide support also changes after hydrogen reduction. On the other hand, both Pd particles with diameters of 2–3nm and 10–20nm on SiO2 show low activity for the water gas shift reaction. Thus, it is concluded that the catalytic activity does not simply depend on the particle size of metals, but that the interaction between metals and metal oxide supports is also important for the catalytic performance.

Predicting crystal structure is one of the most fundamental problems in materials science and a key early step in computational materials design. Ab initio simulation methods are a powerful tool for predicting crystal structure, but are too slow to explore the extremely large space of possible structures for new alloys. Here we describe ongoing work on a novel method (Data Mining of Quantum Calculations, or DMQC) that applies data mining techniques to existing ab initio data in order to increase the efficiency of crystal structure prediction for new alloys. We find about a factor of three speedup in ab intio prediction of crystal structures using DMQC as compared to naïve random guessing. This study represents an extension of work done by Curtarolo, et al. [1] to a larger library of data.

Material science tends to focus around a specific class of materials and devices. After an idea is created, an experiment is postulated, and then materials are grown and devices are fabricated. These materials and devices are characterized using a variety of techniques. Data from these laboratory steps are analyzed, conclusions are formulated, and knowledge is passed on through publications, presentations, and patents. Typically, data are tracked in the area of what is grown and what is measured, but corporate knowledge is often lost as to what motivated certain experiments or what was learned from those experiments. This can be due to many factors including corporate culture, lack of reporting of negative results, and lack of reporting of full data sets. Proper application of informatics must realize that data does not equal knowledge, but is the foundation for creating knowledge, which is far more useful than mere information. Combinatorial approaches for material growth, device fabrication, and subsequent characterization accelerate experimental throughput. Integrating these systems and their data at all levels ultimately will lead to key knowledge to discover new materials and invent new device structures. Well-designed informatics systems must fully relate all types of data and information, make full use of automation, enable data mining, and have an easy-to-use, fast, user interface.

A combinatorial synthesis method was developed by ejecting insoluble oxide suspensions using a drop-on-demand inkjet delivery system. The insoluble oxide suspensions with ultrafine/nano particles were prepared by grinding the oxide power in water using a high-energy ball mill. Using luminescent materials as model systems, it was established that the technique is very well suited to combinatorial synthesis of insoluble oxides.

Our recently introduced “Fiber-Optic Combinatorial Chemistry” technique combines combinatorial synthetic methods and optical fiber sensor technologies. Our one-dimensional combinatorial chemistry method allows for synthesis of large compound libraries in a linear format, for example in the cladding of optical fibers. Subjecting these libraries to assays that indicate positive identification of a library member by the binding of a fluorescent group, produces, in effect, an optical fiber sensor array. The location of a particular fluorescent region along the optical fiber can be determined through the optical time-of-flight technique, in which laser pulses propagating through the fiber core probe through their evanescent fields the fluorescent properties of the compounds located in the fiber cladding. It is a virtue of our combinatorial synthetic procedure that with the location of a compound on the fiber, its synthetic history is immediately known. We demonstrated that limitations on the spatial resolution of compounds along the fiber due to the excited state lifetimes of the fluorescent marker molecules can be overcome by the use of a second fiber - evanescently coupled to the first one - as an optical delay.

The existing claddings of optical fibers severely restrict the range of chemistries for the synthesis of combinatorial libraries. Therefore, in order to make our method more generally applicable, the existing fiber cladding has to be replaced by a porous material that can act as solid support for reactions and at the same time preserve the optical guiding conditions of the fiber. In this contribution we discuss the requirements for such a replacement cladding and evaluate the general suitability of a functionalized candidate material.

We developed a scanning microwave microscope (SμM) designed for characterizing local electric properties at low temperatures. A high-Q λ/4coaxial cavity was used as a sensor probe, which can detect the change of quality factor due to the tip-sample interaction with enough accuracy. From the measurements of combinatorial samples, it was demonstrated that this SμM system has enough performance for high-throughput characterization of sample conductance under variable temperature conditions.