Benchtop X-ray diffraction (XRD) instrument

Powder X-ray diffractometers can readily measure bulk samples provided techniques are devised for sample preparation. In the case of samples in sheet form, such as paper or film, a diffraction pattern with no angular error can be obtained, as shown in Fig. 1, by: (1) Cut the sample to the same size as the aluminum sample plate, (2) Stacking the sample and sample plate, and (3) Set the sample plate into the sample clip. If the sample has enough rigidity and thickness, it should be placed directly onto the sample clip, without using the aluminum sample plate.

In polymer materials processed into the shape of fibers or films, the molecular axes align in the direction of stretching. Therefore, when these types of material are measured, diffraction lines due to crystal faces in specific orientations are observed to be large (preferred orientation). By using this characteristic, and measuring while varying the placement of the sample relative to the scan axis, it is possible to investigate the direction of the molecular axes with respect to the material. In this case, the transmission method is used together with the reflection method.

X-ray diffraction (XRD) in the food and candy industry is crucial to producing a quality product. You would not want to have coconut flavoring in your plain dark chocolate bar or a sweet chocolate to be too bitter. Below is a diffractogram of the milk chocolate specimen shown at the right. The first set of peaks in red is sucrose. The second set in blue is lactose hydrate (essentially dehydrated milk). Finally a few peaks in purple down at 2-7° 2θ can be identified corresponding to the chocolate.

Aluminum oxide or corundum is a commonly available material. However, trace levels of contaminants in the crystal structure of aluminum oxide can result in priceless gems, such as rubies, sapphires, and emeralds. Rubies are corundum with chromium contaminants. It's the chromium that produces the deep red color. Next to diamonds, rubies are the most precious gems. Sapphires come in many different colors: yellow, red, pink, and the more traditional color, blue. The blue color is only possible when titanium and iron are both present in the structure.

The width of the standard incident and receiving Soller slits of the MiniFlex300/600 is 5°, but to obtain high-resolution it is possible to select a width of 2.5° (incident/receiving Soller slits) or a width of 0.5° (receiving Soller slit only). Fig. 1 shows a comparison of the X-ray diffraction profiles of LaB₆ powder when the Soller slit is changed, and Table 1 shows the intensity ratios, and the full width at half maximum (FWHM), which varies proportionally with resolution.

X-ray diffraction (XRD) is an effective method for determination of the phase composition of unknown crystalline and amorphous materials. The analysis is performed by comparing diffraction peak positions and intensity values with the reference patterns of known compounds maintained in the ICDD Powder Diffraction File (PDF). Routine characterization is completed quickly with a minimum of operator involvement. Subsequent analyses, including quantitative analysis of identified phases, are easily accomplished.

Fig. 1 shows the appearance of the MiniFlex600 main unit. The main unit dimensions are 560(W) x 460(D) x 700(H) mm. With a newly developed X-ray generator, it is possible to obtain measurement data with 1.5 times the X-ray diffraction intensity of the previous model, the MiniFlex II. This makes it possible to obtain diffraction intensity approaching that of full-sized models. Fig. 2 shows an intensity comparison between the MiniFlex600, MiniFlex300 and the previous MiniFlex II model.

Forensic laboratories are frequently asked to verify vehicle types or to corroborate eye-witness testimonies. With a sample of the automobile paint and the MiniFlex benchtop X-ray diffractometer, this becomes an achievable assignment! Automobile manufacturer use slightly different paint components and pigments for every model of their vehicles. Every year, the paint formulas change. Using X-ray diffraction, the paint and pigment compositions can be to identified.

X-ray diffraction (XRD) is an excellent analysis technique for identifying unknown solid materials. The XRD pattern can act as a fingerprint to identify unknown materials in crystalline and semi-crystalline samples.

Materials that have a large unit cell with large open space such as zeolites and meso-porous silica are often used as filters, sensors, catalysts, drug delivery devices, etc. because of their cage like crystal structures. X-ray diffraction is one of the techniques often used to study those structures.

The MiniFlex300/600 can be equipped with the D/teX Ultra high-speed 1-dimensional detector to obtain greater intensity. By using this detector, it is possible to obtain intensity a few tens to roughly 100 times greater than a scintillation counter. Using this feature, it is possible to greatly reduce measurement time, detect trace components, and measure micro-samples with high sensitivity. Fig. 1 shows the diffraction profiles obtained with a scintillation counter and the D/teX Ultra high-speed 1-dimensional detector.

The MiniFlex300/600 can be equipped with the D/teX Ultra high-speed 1-dimensional detector to obtain greater intensity. This detector energy resolution, so fluorescent X-rays can be removed from the diffraction pattern without using a diffracted beam monochromator. Fig. 1 shows the X-ray diffraction patterns from measuring hematite in the standard energy range (standard mode) and the energy range enabling removal of fluorescent X-rays due to iron (fluorescent X-ray reduction mode).

For industrial samples, quality control or failure analysis is vital to future product improvements. This polypropylene coated metal sample failed quality control tests due to poor coating adhesions. A section of the coating was removed and the entire sample was inserted in the MiniFlex for testing.

Phase identification using X-ray diffraction (XRD) works much like fingerprint analysis. XRD patterns are collected on unknown samples and compared to patterns obtained from known materials. The primary database for these XRD patterns is compiled and maintained by the International Center for Diffraction Data (ICDD). In some industrial cases the preferred XRD patterns for optimal analysis of a specific process may not be present in the ICDD database.

The oil drilling industry can encounter a wide variety of samples, including rocks, scales, cements, cuttings, and muds throughout the drilling process. X-ray diffraction (XRD) is an essential tool for phase identification analysis of these commonly identified solids in the oil field. Three phases are identified in the figure below; the major is a barite phase and the two minor phases consist of calcite and quartz. The primary goal of this application is to quickly identify the phases contained within the sample material.

A common marketing approach in the cosmetics industry today is the branding of natural products. These natural cosmetics claim to use natural ingredients for effects such shine, whitening, and sun protection. X-ray diffraction (XRD ) is an excellent technique to identify the composition of materials in the cosmetics industry. As an example four brands of so called "natural" cosmetic foundations were analyzed for composition using the MiniFlex benchtop diffractometer. The scans and phase identification results can be seen in figures 1 through 4.

Ensuring quality control can be a daunting task in industrial processes. The key to a quality product is to maintain that quality throughout the entire process and having the appropriate materials is essential to this accomplishment. The wrong materials could alter the properties of the desired product. It could even change the product and everyone would certainly want the finished product to be able to function with its desired task. Observe the white powder in Figure 1.

Zeolites are commonly used in a vast variety of industrial applications, including environmental clean-up, petroleum cracking, filtering/separations and cation exchange. These materials can be mined from natural sources or can be commercially synthesized. A basic structure of five silicon and aluminum tetrahedra result in a cage-like structure with large open spaces or "pores". These pores have charged regions which attract or exchange cations. For effective activity and specific cation incorporation, the zeolites need to be very specific and pure.

Steels and steel alloys are an essential component in many everyday applications. Quality control is crucial to maintaining the structural stability of these materials. During the processing of these heat-treated steel alloys, austenite may be retained which could weaken the overall structural integrity of the material used to build our buildings, cars, bridges and much more. In this experiment retained austenite analysis was performed on a typical metal sample.

Petroleum products are essential to the world's operation. In order to keep the petroleum industries flowing, scale buildup must be reduced. Whether your interest is in scales, cuttings, cements or muds in the drilling industry; phase identification analysis using X-ray diffraction (XRD) is an important tool in this industry. The primary goal of this application is to quickly identify the phases contained within the sample material. Data collection with the MiniFlex combined with data reduction and Search/Match analysis using the Jade software package made simple work out of this material.

Molybdenum silicide (MoSi₂) is a refractory ceramic and often used in heating elements. In production of MoSi₂, other Mo-Si intermetallic compounds such as Mo₅Si₃ could form. It is important to analyze the purity of MoSi₂ to control the properties of the heating elements. Powder XRD method is suitable to quantify MoSi₂ purity since it can clearly differentiate MoSi₂ from other Mo-Si intermetallic compounds.

Many products are not regulated by a governing body. Quality control is in the hands of those who use these products. For example, Figure 1 shows a white powder from a bottle labeled "talc." When this powder was run on the MiniFlex, talc was observed only in trace quantities (Figure 2). Talc is typically identified as magnesium silicate hydroxide. However, this material is primarily composed of calcite and dolomite identified as calcium/magnesium carbonate (Figure 3).

The MiniFlex300/600 can be equipped with the D/teX Ultra high-speed 1-dimensional detector to obtain greater intensity. This detector has a broad detection surface and can efficiently count diffraction X-rays from a sample. As a result, it is possible to obtain intensities from a few tens to roughly 100 times greater than a scintillation counter. Background can also be reduced using the fluorescent X-ray reduction mode, or knife edge etc. Fig. 1 shows the X-ray diffraction patterns obtained when a knife edge is installed versus no knife edge.

Ever wonder why that particular pastry is so good? Well the food science industry does! They closely monitor the composition of their products to ensure that it continues to taste, smell and look appealing. Of the many analytical techniques used for quality control, X-ray diffraction ("XRD") is probably one of the least advertised but most widely employed. This technique is used for everything from compound identification, quality control, quantification, and even to measure crystalline quality.