著者が感謝する 2 つの匿名査読したいし、ゼウス上級エディター博士アリーシャ恵理子の貴重なコメントを確認します。この研究は、6 BM B アルゴンヌ国立研究所で高度な光子ソース (AP) ので行われました。鉱物物理学研究所、ストーニーブ ルック校、材料特性研究国立科学財団 (NSF) の共同契約耳耳 1661511 11-57758 地球科学 (詳しい) のコンソーシアムによってこの施設の使用になりました大学。著者は、耳 1141895、耳 1045629 耳 1361463 このプログラムのために研究資金 NSF を認めます。この研究に使用される光子の高度なソースのリソース、科学ユーザー施設米国エネルギー省 (DOE) オフィス運営アルゴンヌ国立研究所によってエネルギー省科学局契約 DEAC02 06CH11357 の下で。セル ・ アセンブリは詳しいマルチアンビル細胞アセンブリ開発プロジェクトにあります。リクエスト (scheung9@wisc.edu) の作成者にはすべてのデータ ファイルがあります。サンプルやデータは、ストーニブ ルック大学で鉱物物理学研究所でアーカイブされます。

著者は利益相反を宣言しません。

6 BM B のマルチ アンビル ・ セルを用いた x 線回折実験を行うための詳細な手順を提案します。おそらく上記のプロトコルの最も重要なまだ最も困難なステップを含む、サンプルの品質を最適化します。サンプルの質のような重要性は、ほとんどすべての岩や鉱物の変形実験に適用されます。まず、フラット、両端同時に、円筒の表面に垂直に互いに平行とする岩石コアの端面にとって重要で...

この記事で紹介した方法の後ろの理論的根拠は、岩石と鉱物骨材試料内にある圧縮とその後の圧密時の応力分布を定量化することです。貯水池と地盤工学8,17,18,19,20,28 に非常に重要な岩石・鉱物集合体の圧縮を理解することが ,33。圧縮は、気孔率を減らすために機能し、したがって、間隙水圧の上昇に 。間隙水圧のような増加は、効果的な圧力35の減少に します。結果は貯留岩が崩れし、従ってより低い応力での早期の失敗を受けることができます。地下に塑性変形の結果のいくつかの例: 石油とガス貯留層28,33, 維持の長期生産の障害は表面沈下8,18,19,20、および流体の流れパターン17の変化。したがって、圧縮の包括的な知識を岩で処理し、鉱物の集合体がそのような潜在的悪影響の可能性を減らすに役立つ可能性が。
ここで強調表示法を使用しての大きな利点は、外部に対してグローバルに平均地盤5,6内内部の応力分布を定量化する手段適用圧力12を提供することです。,22します。 さらに、その場で実験応力分布の進化は時間分解。外部の圧力では、比較的低い値 (数十メガパスカル) から高い値 (複数ギガパスカル) までの範囲と見なされます。サンプル内の圧力は、局所弾性歪5,6の尺度として個々 の鉱物粒子の原子の格子間隔を使用して直接に測定されます。白または単色 x 線モードで一般 x 線の援助と原子の格子間隔が決定されます。10 要素 Ge 検出器 (の配列が 1 つだけではなく、白い x 線モード (例えば、DDIA 6BM B ビームラインの高度な光子ソース (AP)、アルゴンヌ国立研究所)、x 線の回折ビームの強度が決定されます。図 1) 0 °、22.5 °、45 °、67.5 °、90 °、112.5 °、135 °、157.5 °、180 °、270 ° の方位角の角度で固定円に沿って分散します。単色 x 線モード CCD 検出器 (例えば、 DDIA 30 13 ID D ビームライン GSECARS、APS、アルゴンヌ国立研究所)18,23を使用して回折パターンが記録されます。両方の x 線モードは、さまざまな方向の応力がどのように変化の定量化を許可します。このアプローチは、地盤材料の圧縮のすべての以前の研究から根本的に異なる。
典型的な圧縮の研究で筒状のサンプルは、アクチュエータ25断面積に適用される軸力による圧縮されます。このような条件下で応力振幅の大きさがサンプルの初期断面積 (ロードセルにより測定) 軸力を単に割ることによって計算されます。それは、この応力の大きさだけ、一括の平均値はなど、現実的に表さないローカル応力状態が変化、か複雑な異種、粒状材料の内で配布されて注意してください。その後圧縮し、堆積・続成過程1,7,による超硬合金鉱物粒子の凝集による複雑な粒状材料の例としては、砕屑性の堆積岩が形成されます。21,30,31. これらの凝集体は当然ながら二次解散した穀物包装の形状から固有の穀物間の空隙を含む毛穴を継承します。したがって、任意の応力はによってサポートされる予定あり集中つぶつぶに連絡先と粒孔インターフェイスに消えます。
粒状材料内の応力変動の複雑さに加えてさらに他の要因は、これらのシナリオで勉強して圧縮を複雑にします。まず、局所応力分布は任意の砕屑性堆積岩の中で必然的に存在している組織成果物 (例えば、粒子形状、既存の骨折) による変更に対して脆弱です。第二に、サンプル表面に作用する応力の大きさは完全に定量化することができます、サンプル体内の応力分布に悪い拘束された残った。終わり効果32 -境界効果読み込みラムズとフェースの摩擦によるサンプル間の接触に近い平均応力が集中しているという-圧縮で読み込まれる円筒形のサンプルで展示するのに知られています。例としては、鵬26は内様々 な終了条件に供した花崗岩の一軸圧縮ひずみの不均一性を示した。したがって、粒状材料の局所応力分布を正確に計算するため提案する岩や鉱物の集合体の x 線回折 (XRD) 実験を実行するための次の詳細なプロトコルで変形マルチアンビル装置を用いたビームライン 6-バミューダ諸島-B アルゴンヌ国立研究所で AP の。

<table><tbody><tr><td>Rotatory Tool Workstation Drill Press Work Station with Wrench</td><td>Dremel</td><td>220-01</td><td></td></tr><tr><td>MultiPro Keyless Chuck</td><td>Dremel</td><td>4486</td><td></td></tr><tr><td>Variable-Speed Rotatory Tool&amp;nbsp;</td><td>Dremel</td><td>4000-6/50</td><td></td></tr><tr><td>Super small Diamond Core Drill - 2.5 mm</td><td>Dad&#039;s Rock Shop</td><td>SDCD</td><td></td></tr><tr><td>Coolant</td><td>NBK</td><td>JK-A-NBK-000-020</td><td>Grinding Fluid Concentrate US 5 gal / 20 L</td></tr><tr><td>commercial software package and codes for instrument control and data acquisition</td><td>IDL EPICS and SPEC</td><td></td><td>installed on the computer at the beamline</td></tr><tr><td>CCD Camera</td><td>Allied Vision</td><td>Prosilica GT</td><td>installed at the beamline</td></tr></tbody></table>

stress distribution during cold compression of rocks and mineral aggregates using synchrotron-based x-ray diffraction

岩およびマルチアンビル変形試験機 (D DIA) が放射光 x 線と相まって内ミネラル総計の圧縮実験を実行するための詳細な手順を報告する.キューブ状のサンプル アセンブリは準備、圧縮、常温で 4 x 線透過ダイアモンドアンビル、横方向と縦方向の平面の 2 つのタングステン カーバイド アンビルのセットによってそれぞれ。すべて 6 アンビルは 250 トン油圧プレス内に収容され、同時に 2 つのくさびガイド ブロックで内側に押し込まれ。水平のエネルギー分散型 x 線ビームを介して投影は、サンプル アセンブリによって回折します。ビームは白または単色 x 線モードでは一般的です。白色 x 線の場合回折 x 線検出結果のエネルギー分散回折パターンを収集する固体検出器アレイです。単色 x 線の場合は電荷結合素子 (CCD) 検出器やイメージング プレートなど、二次元 (2 D) 検出器を用いた回折パターンを記録します。2 D の回折格子間隔を導出する分析されます。サンプルの弾性ひずみは、粒内での原子の格子間隔から派生します。ストレスは、あらかじめ決められた弾性率と弾性ひずみを使用して計算されます。さらに、2 次元応力分布の向きが異なる応力を分散する方法を理解できます。さらに、x 線パスのシンチレータ降伏体積歪データ サンプルの直接測定実験中にサンプル長変化の精密測定は、サンプル環境の可視光の画像が得られます。このタイプの実験は、圧縮のメカニズムに光を当てることができます最終的に地盤材料内の応力分布を定量化できます。そのような知識圧縮プロセスが重要な岩石力学、地盤工学、鉱物の物理学および物質科学アプリケーションにおける主要なプロセスの私達の理解を大幅に向上する可能性があります。

複合水晶集計5,6と novaculite コア サンプル66BM b マルチアンビル プレスで実行 x 線回折実験 (実験 SIO2_55) から 1 つの代表の結果の例を示す.石英集合体と novaculite の粒径、~ 4 μ m 〜 6-9 μ m、それぞれ5,6。図 8にこの実験中に収集されたスペクト...

Watch this Scientific Journal Video about Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction at JoVE.com

Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction

岩や放射光 x 線と相まって変形マルチアンビル装置内ミネラル総計を圧縮実験の手順の詳細を報告します。そのような実験は、最終的に地盤材料の圧縮プロセスのライトを取除くことのサンプル内の応力分布の定量化を許可します。

岩や放射光 x 線回折を用いた鉱物骨材の冷間圧縮時の応力分布

We report detailed procedures for performing compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus (D-DIA) ...

stress-distribution-during-cold-compression-rocks-mineral-aggregates

Universidad San Sebastian

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Education

JoVE Core

JoVE Journal

Mechanical Engineering

Environment

Unit 1

Principal Stresses under a Given Loading

SCIENTISTS IN ACTION

9.6K ビュー.  Stony Brook University. 岩や放射光 x 線と相まって変形マルチアンビル装置内ミネラル総計を圧縮実験の手順の詳細を報告します。そのような実験は、最終的に地盤材料の圧縮プロセスのライトを取除くことのサンプル内の応力分布の定量化を許可します。

ビデオ: Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction

Measuring Fluxes of Mineral Nutrients and Toxicants in Plants with Radioactive Tracers

Unidirectional influx and efflux of nutrients and toxicants, and their resultant net fluxes, are central to the nutrition and toxicology of plants. Radioisotope tracing is a major technique used to measure such fluxes, both within plants, and between plants and their environments. Flux data obtained with radiotracer protocols can help elucidate the capacity, mechanism, regulation, and energetics of transport systems for specific mineral nutrients or toxicants, and can provide insight into compartmentation and turnover rates of subcellular mineral and metabolite pools. Here, we describe two major radioisotope protocols used in plant biology: direct influx (DI) and compartmental analysis by tracer efflux (CATE). We focus on flux measurement of potassium (K+) as a nutrient, and ammonia/ammonium (NH3/NH4+) as a toxicant, in intact seedlings of the model species barley (Hordeum vulgare L.). These protocols can be readily adapted to other experimental systems (e.g., different species, excised plant material, and other nutrients/toxicants). Advantages and limitations of these protocols are discussed.

In planta measurement of nutrient and toxicant fluxes is essential to the study of plant nutrition and toxicity. Here, we cover radiotracer protocols for influx and efflux determination in intact plant roots, using potassium (K+) and ammonia/ammonium (NH3/NH4+) fluxes as examples. Advantages and limitations of such techniques are discussed.

放射性トレーサーで植物にミネラル栄養素や毒性物質のフラックスを測定する

Unidirectional influx and efflux of nutrients and toxicants, and their resultant net fluxes, are central to the nutrition and toxicology of plants. ...

環境学

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

エクストリーム圧力と温度での合成とMicrodiffraction

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

工学

Extracting Metrics for Three-dimensional Root Systems: Volume and Surface Analysis from In-soil X-ray Computed Tomography Data

Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to climate change and crop management. Quantitative size information on roots in their native environment is invaluable for studying root growth and environmental processes involving plants. X-ray computed tomography (XCT) has been demonstrated to be an effective tool for in situ root scanning and analysis. We aimed to develop a costless and efficient tool that approximates the surface and volume of the root regardless of its shape from three-dimensional (3D) tomography data. The root structure of a Prairie dropseed (Sporobolus heterolepis) specimen was imaged using XCT. The root was reconstructed, and the primary root structure was extracted from the data using a combination of licensed and open-source software. An isosurface polygonal mesh was then created for ease of analysis. We have developed the standalone application imeshJ, generated in MATLAB1, to calculate root volume and surface area from the mesh. The outputs of imeshJ are surface area (in mm2) and the volume (in mm3). The process, utilizing a unique combination of tools from imaging to quantitative root analysis, is described. A combination of XCT and open-source software proved to be a powerful combination to noninvasively image plant root samples, segment root data, and extract quantitative information from the 3D data. This methodology of processing 3D data should be applicable to other material/sample systems where there is connectivity between components of similar X-ray attenuation and difficulties arise with segmentation.

A methodology for obtaining visual and quantitative root structure information from X-ray computed tomography data acquired in-soil is presented.

三次元根系のための抽出メトリック：イン土壌のX線コンピュータ断層撮影データからボリュームおよび表面分析

Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to ...

High-pressure, High-temperature Deformation Experiment Using the New Generation Griggs-type Apparatus

In order to address geological processes at great depths, rock deformation should ideally be tested at high pressure (&#62; 0.5 GPa) and high temperature (&#62; 300 &#176;C). However, because of the low stress resolution of current solid-pressure-medium apparatuses, high-resolution measurements are today restricted to low-pressure deformation experiments in the gas-pressure-medium apparatus. A new generation of solid-medium piston-cylinder (&#34;Griggs-type&#34;) apparatus is here described. Able to perform high-pressure deformation experiments up to 5 GPa and designed to adapt an internal load cell, such a new apparatus offers the potential to establish a technological basis for high-pressure rheology. This paper provides video-based detailed documentation of the procedure (using the &#34;conventional&#34; solid-salt assembly) to perform high-pressure, high-temperature experiments with the newly designed Griggs-type apparatus. A representative result of a Carrara marble sample deformed at 700 &#176;C, 1.5 GPa and 10-5 s-1 with the new press is also given. The related stress-time curve illustrates all steps of a Griggs-type experiment, from increasing pressure and temperature to sample quenching when deformation is stopped. Together with future developments, the critical steps and limitations of the Griggs apparatus are then discussed.

Rock deformation needs to be quantified at high pressure. A description of the procedure to perform deformation experiments in a newly designed solid-medium Griggs-type apparatus is here given. This provides technological basis for future rheological studies at pressures up to 5 GPa.

新世代グリッグス型装置を使用して、高温高圧変形実験

In order to address geological processes at great depths, rock deformation should ideally be tested at high pressure (&#62; 0.5 GPa) and high temperature ...

High Pressure Single Crystal Diffraction at PX^2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe2+0.14Fe3+0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 &#177;0.006 &#197;, b = 8.761 &#177;0.004 &#197;, c = 5.248 &#177;0.001 &#197;, &#946; = 105.06 &#177;0.03&#186;, &#945; = &#947; = 90&#186;.

In this report, we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell at the GSECARS 13-BM-C beamline at the Advanced Photon Source. ATREX and RSV programs are used to analyze the data.

PX ^ 2の高圧単結晶回折

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

化学

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.

・鉱物及び岩石試料の蛍光を放射光 x 線回折

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

Visualization of Failure and the Associated Grain-Scale Mechanical Behavior of Granular Soils under Shear using Synchrotron X-Ray Micro-Tomography

The rapid development of X-ray imaging techniques with image processing and analysis skills has enabled the acquisition of CT images of granular soils with high-spatial resolutions. Based on such CT images, grain-scale mechanical behavior such as particle kinematics (i.e., particle translations and particle rotations), strain localization and inter-particle contact evolution of granular soils can be quantitatively investigated. However, this is inaccessible using conventional experimental methods. This study demonstrates the exploration of the grain-scale mechanical behavior of a granular soil sample under triaxial compression using synchrotron X-ray micro-tomography (&#956;CT). With this method, a specially fabricated miniature loading apparatus is used to apply confining and axial stresses to the sample during the triaxial test. The apparatus is fitted into a synchrotron X-ray tomography setup so that high-spatial resolution CT images of the sample can be collected at different loading stages of the test without any disturbance to the sample. With the capability of extracting information at the macro scale (e.g., sample boundary stresses and strains from the triaxial apparatus setup) and the grain scale (e.g., grain movements and contact interactions from the CT images), this procedure provides an effective methodology to investigate the multi-scale mechanics of granular soils.

The protocol describes procedures to acquire high-spatial resolution computed tomography (CT) images of a granular soil during triaxial compression, and to apply image processing techniques to these CT images to explore the grain-scale mechanical behavior of the soil under loading.

シンクロトロンX線マイクロ断層撮影によるせん断下の粒状土壌の故障の可視化と関連する粒状土壌の機械的挙動

The rapid development of X-ray imaging techniques with image processing and analysis skills has enabled the acquisition of CT images of granular soils ...

An Externally-Heated Diamond Anvil Cell for Synthesis and Single-Crystal Elasticity Determination of Ice-VII at High Pressure-Temperature Conditions

The externally-heated diamond anvil cell (EHDAC) can be used to generate simultaneously high-pressure and high-temperature conditions found in Earth&#8217;s and planetary interiors. Here we describe the design and fabrication of the EHDAC assemblies and accessories, including ring resistive heaters, thermal and electrical insulating layers, thermocouple placement, as well as the experimental protocol for preparing the EHDAC using these parts. The EHDAC can be routinely used to generate megabar pressures and up to 900 K temperatures in open air, and potentially higher temperatures up to ~1200 K with a protective atmosphere (i.e., Ar mixed with 1% H2). Compared with a laser-heating method for reaching temperatures typically &#62;1100 K, external heating can be easily implemented and provide a more stable temperature at &#8804;900 K and less temperature gradients to the sample. We showcased the application of the EHDAC for synthesis of single crystal ice-VII and studied its single-crystal elastic properties using synchrotron-based X-ray diffraction and Brillouin scattering at simultaneously high-pressure high-temperature conditions.

This work focuses on the standard protocol for preparing the externally-heated diamond anvil cell (EHDAC) for generating high-pressure and high-temperature (HPHT) conditions. The EHDAC is employed to investigate materials in Earth and planetary interiors under extreme conditions, which can be also used in solid state physics and chemistry studies.

高圧温度条件下でのIce-VIIの合成と単結晶弾性測定のための外部加熱ダイヤモンドアンビルセル

The externally-heated diamond anvil cell (EHDAC) can be used to generate simultaneously high-pressure and high-temperature conditions found in ...

Determining the Mechanical Strength of Ultra-Fine-Grained Metals

The mechanical strengthening of metals is the long-standing challenge and popular topic of materials science in industries and academia. The size dependence of the strength of the nanometals has been attracting a lot of interest. However, characterizing the strength of materials at the lower nanometer scale has been a big challenge because the traditional techniques become no longer effective and reliable, such as nano-indentation, micropillar compression, tensile, etc. The current protocol employs radial diamond-anvil cell (rDAC) X-ray diffraction (XRD) techniques to track differential stress changes and determine the strength of ultrafine metals. It is found that ultrafine nickel particles have more significant yield strength than coarser particles, and the size strengthening of nickel continues down to 3 nm. This vital finding immensely depends on effective and reliable characterizing techniques. The rDAC XRD method is expected to play a significant role in studying and exploring nanomaterial mechanics.

The protocol presented here describes the high-pressure radial diamond-anvil-cell experiments and analyzing the related data, which are essential for obtaining the mechanical strength of the nanomaterials with a significant breakthrough to the traditional approach.

超微細金属の機械的強度の決定

The mechanical strengthening of metals is the long-standing challenge and popular topic of materials science in industries and academia. The size ...

Single Crystal and Powder X-ray Diffraction

Source: Tamara M. Powers, Department of Chemistry, Texas A&#38;M University&#160;
X-ray crystallography is a technique that uses X-rays to study the structure of molecules. X-ray diffraction (XRD) experiments are routinely carried out with either single-crystal or powdered samples.
Single-crystal XRD:
Single-crystal XRD allows for absolute structure determination. With single-crystal XRD data, the exact atomic positions can be observed, and thus bond lengths and angles can be determined. This technique provides the structure within a single crystal, which does not necessarily represent the bulk of the material. Therefore, additional bulk characterization methods must be utilized to prove the identity and purity of a compound.
Powder XRD:
Unlike single-crystal XRD, powder XRD looks at a large sample of polycrystalline material and therefore is considered a bulk characterization technique. The powder pattern is considered a &#34;fingerprint&#34; for a given material; it provides information about the phase (polymorph) and crystallinity of the material. Typically, powder XRD is used to study minerals, zeolites, metal-organic frameworks (MOFs), and other extended solids. Powder XRD can also be used to establish bulk purity of molecular species.
Previously, we have seen how to grow X-ray quality crystals (see video in Essentials of Organic Chemistry series). Here we will learn the principles behind XRD. We will then collect both single-crystal and powder data on Mo2(ArNC(H)NAr)4, where Ar = p-MeOC6H5.

単結晶および粉末 x 線回折

Source: Tamara M. Powers, Department of Chemistry, Texas A&#38;M University&#160;
X-ray crystallography is a technique that uses X-rays to study the ...