Since the inception of 3D printing, an evolutionary process has taken place in which specific user and customer needs have crossed paths with the capabilities of a growing number of machines to create value-added businesses. Even today, over 30 years later, the growth of 3D printing and its utilization for the good of society is often limited by the various users' understanding of the technology for their specific needs. This article presents an overview of current 3D printing technologies and shows numerous examples from a multitude of fields from manufacturing to education.

The new nonlinear optical crystal Y x La y Sc z (BO3)4 (x + y + z = 4) has been discovered. Phase boundaries have been established in the determination of the x, y, z composition parameters that define the existence region of the trigonal huntite-type structure. From single-crystal X-ray diffraction measurements, the member Y0.57La0.72Sc2.71(BO3)4 has been found to crystallize in space group R32 with cell dimensions a = 9.774(1) and c = 7.944(3) Å. Large single crystals have been grown by a high-temperature solution method. The high-energy optical absorption edge for polished pieces was found to be at a wavelength shorter than 200 nm. Sellmeier equations for the dispersion in the refractive indices were determined on the basis of curve fitting of data obtained by the method of minimum deviation. From modeling and optical measurements on powders, the nonlinear optical coefficient d 11 has been determined to be 1.4 pm/V.

The color of a gemstone is inextricably linked to its chemical composition, yet the quantitative relationship between color and chemistry is poorly understood in most cases. Here we use corundum to present a comprehensive quantitative description of the causes of color in a gem material and illustrate its predictive power. Natural corundum has six major chromophores that cause color: Cr 3+ , h • -Cr 3+ , Fe 3+ , h • -Fe 3+ , Fe 2+ -Ti 4+ , and V 3+ . We use synthetic samples doped with a single chromophore to study their light absorption behavior in isolation. Natural samples are used as well to study single chromophores, and we can subtract out the absorption of additional chromophores that might be present. Combining quantitative visible absorption spectroscopy with chemical analysis by SIMS, we are able to calculate the absorption cross section of each chromophore. The absorption cross section information is used to determine the depth of color that would occur in corundum of a given size (optical path length) containing a specific chromophore of a given concentration.

= 4). -Large single crystals of approximate composition Y0.57La0.72Sc2.71(BO3)4 are prepared from mixtures of Y2O3, La2O3, Sc2O3, B2O3, and Li2O using 3Li2O·2B2O3 as flux (1050°C, 2 d). The compound crystallizes in the trigonal space group R32 with Z = 3. Measurements of the optical properties indicate a wide transparency range extending into the deep UV, a moderate birefringence, and a high second-order susceptibility coefficient. These features make the compound a promising nonlinear optical material for practical applications. -(YE, N.; STONE-SUNDBERG, J. L.; HRUSCHKA, M. A.; AKA, G.; KONG, W.; KESZLER*, D. A.; Chem. Mater. 17 (2005) 10, 2687-2692; Dep. Chem., Oreg. State Univ., Corvallis, OR 97331, USA; Eng.) -W. Pewestorf 30-014

Ongoing software developments for creating three-dimensional (3D) printed crystallographic models seamlessly from Crystallographic Information Framework (CIF) data (*.cif files) are reported. Color versus monochrome printing is briefly discussed. Recommendations are made on the basis of our preliminary printing efforts. A brief outlook on new materials for 3D printing is given.

Methods and outcomes for teaching crystallography in graduate, post-graduate and secondary school environments are presented. This is an extended report based on the ideas presented in the MS92 Microsymposium at the IUCr 23rd Congress and General Assembly in Montreal.

No abstract

No abstract