A contribution to the development of wide band-gap nonlinear optical and laser materials

The primary focus of this work is on examining structure-property relationships of interest for high-power nonlinear optical and laser crystals. An intuitive and simply illustrated method for assessing the nonlinear optical potential of structurally characterized noncentrosymmetric materials is introduced. This method is applied to materials including common quartz and tourmaline and then extended to synthetic materials including borates, silicates, aluminates, and phosphates. Particularly, the contributions of symmetric tetrahedral and triangular anionic groups are inspected. It is shown that both types of groups significantly contribute to the optical frequency converting abilities of noncentrosymmetric crystals. In this study, several known materials are included as well as several new materials. The roles of the orientation, composition, and packing density of these anionic groups are also discussed. The structures and optical properties of the known materials BPO₄, NaAlO₂, LaCa₄O(BO₃)₃, and tourmaline; the new compounds La₀.₈Y₀.₂Sc₃(BO₃)₄ and Ba₂B₁₀O₁₇; and the laser host Sr₃Y₀.₇₅Yb₀.₂₅(B0₃)₃ are described

3D Printing & Open Access Databases for Crystallographic College Education

Presentation gives an overview of available open access databases of crystals and crystal structures, as well as discussions of how newly developed 3D printing technologies can be used to teach crystallography at the college level. Offers advice regarding conversion of crystallographic information files to 3D printing files, and shares news from the 3D printing of crystallographic models community

Crystallographic Education in the 21st Century

There are many methods that can be used to incorporate concepts of crystallography into the learning experiences of students, whether they are in elementary school, at university or part of the public at large. It is not always critical that those who teach crystallography have immediate access to diffraction equipment to be able to introduce the concepts of symmetry, packing or molecular structure in an age- and audience-appropriate manner. Crystallography can be used as a tool for teaching general chemistry concepts as well as general research techniques without ever having a student determine a crystal structure. Thus, methods for younger students to perform crystal growth experiments of simple inorganic salts, organic compounds and even metals are presented. For settings where crystallographic instrumentation is accessible (proximally or remotely), students can be involved in all steps of the process, from crystal growth, to data collection, through structure solution and refinement, to final publication. Several approaches based on the presentations in the MS92 Microsymposium at the IUCr 23rd Congress and General Assembly are reported. The topics cover methods for introducing crystallography to undergraduate students as part of a core chemistry curriculum; a successful short-course workshop intended to bootstrap researchers who rely on crystallography for their work; and efforts to bring crystallography to secondary school children and non-science majors. In addition to these workshops, demonstrations and long-format courses, open-format crystallographic databases and three-dimensional printed models as tools that can be used to excite target audiences and inspire them to pursue a deeper understanding of crystallography are described

Accurate Trace Element Reporting in Corundum: Development of Secondary Ion Mass Spectrometry Relative Sensitivity Factors

The attractive physical and chemical properties of corundum lend to this material’s importance in both its natural and synthetic forms. However, much of the quantitative work performed on this material is plagued by unknown inaccuracy as non‐matrix matched reference materials are used. To conduct accurate quantitative analysis using SIMS, matrix‐specific relative sensitivity factors (RSFs) were determined for eighteen trace elements in corundum using dose‐verified ion‐implants. The RSF values ranged from 2.56 × 10²² cm⁻¹ to 3.29 × 10²⁴ with total combined uncertainty values ranging from 7–10%. The RSF values, which are related to ionisation potentials, showed trends consistent with expectations for an insulating oxide. The developed values were applied to calibrate reference materials for LA‐ICP‐MS and to study other natural and synthetic corundum samples. A measurement reference material calibrated for Mg, Si, Ti, V, Fe and Ga produced consistent results over ten sessions in four years with relative standard deviations per trace element of 5% or less, confirming the repeatability of our process. A key finding was that calibrating LA‐ICP‐MS with NIST SRM 610 and 612 glasses to analyse corundum resulted in under‐reporting trace elements Be, Ti, V, Fe, Co, Ni and Ga compared with using matrix‐matched reference materials

Accurate Trace Element Reporting in Corundum: Development of Secondary Ion Mass Spectrometry Relative Sensitivity Factors

The attractive physical and chemical properties of corundum lend to this material’s importance in both its natural and synthetic forms. However, much of the quantitative work performed on this material is plagued by unknown inaccuracy as non‐matrix‐matched reference materials are used. To conduct accurate quantitative analysis using SIMS, matrix‐specific relative sensitivity factors (RSFs) were determined for eighteen trace elements in corundum using dose‐verified ion implants. The RSF values ranged from 2.56 × 1022 to 3.29 × 1024 cm‐1 with total combined uncertainty values ranging from 7 to 10%. The RSF values, which are related to ionisation potentials, showed trends consistent with expectations for an insulating oxide. The developed values were applied to calibrate reference materials for LA‐ICP‐MS and to study other natural and synthetic corundum samples. A measurement reference material calibrated for Mg, Si, Ti, V, Fe and Ga produced consistent results over ten sessions in 4 years with relative standard deviations per trace element of 5% or less, confirming the repeatability of our process. A key finding was that calibrating LA‐ICP‐MS with NIST SRM 610 and 612 glasses to analyse corundum resulted in under‐reporting trace elements Be, Ti, V, Fe, Co, Ni and Ga compared with using matrix‐matched reference materials

Accurate Trace Element Reporting in Corundum: Development of Secondary Ion Mass Spectrometry Relative Sensitivity Factors

The attractive physical and chemical properties of corundum lend to this material’s importance in both its natural and synthetic forms. However, much of the quantitative work performed on this material is plagued by unknown inaccuracy as non‐matrix matched reference materials are used. To conduct accurate quantitative analysis using SIMS, matrix‐specific relative sensitivity factors (RSFs) were determined for eighteen trace elements in corundum using dose‐verified ion‐implants. The RSF values ranged from 2.56 × 10²² cm⁻¹ to 3.29 × 10²⁴ with total combined uncertainty values ranging from 7–10%. The RSF values, which are related to ionisation potentials, showed trends consistent with expectations for an insulating oxide. The developed values were applied to calibrate reference materials for LA‐ICP‐MS and to study other natural and synthetic corundum samples. A measurement reference material calibrated for Mg, Si, Ti, V, Fe and Ga produced consistent results over ten sessions in four years with relative standard deviations per trace element of 5% or less, confirming the repeatability of our process. A key finding was that calibrating LA‐ICP‐MS with NIST SRM 610 and 612 glasses to analyse corundum resulted in under‐reporting trace elements Be, Ti, V, Fe, Co, Ni and Ga compared with using matrix‐matched reference materials

The Role of Silicon in the Color of Gem Corundum

Natural corundum is colored by a variety of trace-element impurities and by the chemical reactions among them. Important to nearly all of the colors is the role played by the reactions among silicon, titanium, and magnesium. Characterization of the interactions between these aliovalent ions has been hindered by the fact that the laser ablation–inductively coupled quadrupole–mass spectrometry equipment used in most gem labs does not resolve the interferences for silicon. Thus Si has not been measured at relevant concentrations. Recent development of ion implant standards and the application of secondary ion mass spectrometry has allowed the accurate measurement of silicon in corundum for the first time. As an example of its importance, detailed analyses of sapphire from Montana’s Yogo Gulch deposit are presented. These analyses show that without silicon, Yogo sapphire would not be blue

Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

To improve the accuracy and efficiency of trace element analysis in ruby and sapphire, standards sets containing matrix-matched corundum with targeted levels of beryllium, magnesium, silicon, titanium, vanadium, chromium, iron, and gallium were created. Ultra-high-purity corundum was also incorporated as a “true matrix zero.” To our knowledge, these sets contain the most accurate standards for the key trace elements in corundum today. The standards were designed to cover the optimal range of the main trace elements typically characterized in natural ruby and sapphire. Additionally, we were able to accurately quantify silicon in corundum by successfully resolving the ^(28)Si^+ peak from the ^(27)Al^1H^+ peak using the superior mass resolving power of secondary ion mass spectrometry (SIMS) as compared to laser ablation–inductively coupled plasma–quadrupole mass spectrometry (LA-ICP-QMS)

Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

To improve the accuracy and efficiency of trace element analysis in ruby and sapphire, standards sets containing matrix-matched corundum with targeted levels of beryllium, magnesium, silicon, titanium, vanadium, chromium, iron, and gallium were created. Ultra-high-purity corundum was also incorporated as a “true matrix zero.” To our knowledge, these sets contain the most accurate standards for the key trace elements in corundum today. The standards were designed to cover the optimal range of the main trace elements typically characterized in natural ruby and sapphire. Additionally, we were able to accurately quantify silicon in corundum by successfully resolving the ^(28)Si^+ peak from the ^(27)Al^1H^+ peak using the superior mass resolving power of secondary ion mass spectrometry (SIMS) as compared to laser ablation–inductively coupled plasma–quadrupole mass spectrometry (LA-ICP-QMS)

3D Systems\u27 Technology Overview and New Applications in Manufacturing, Engineering, Science, and Education

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\u27 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