Discovery Of X-ray Diffraction Research Articles

When is a Lattice Not a Lattice? The changing meaning of the term lattice in crystallography and physics

The concept of the lattice is central to the understanding of crystalline solids. However, usage of this word can very often differ between crystallographers, for whom a lattice is a mathematical object that describes the symmetry of a crystal, and physicists and chemists, for whom lattice is commonly used as a word for a regular array of particles. The similarity between the two definitions means they can easily be confused by students or inexperienced practitioners, but the fundamental differences can make the consequences of such confusion significant, an issue rarely tackled directly in popular textbooks. Here we examine the historical roots of this problem of context, and the changing understanding of the word ‘lattice’ over time. While the origins of the term lattice lie with the 19th century mathematical crystallographers, their usage, both in terms of the words used and their meanings, was fluid, and no strong distinction between the lattice and the physical components of a crystal was made. Leading crystallographers in the early 20th century regularly used the word lattice in a way that is unacceptable to some of their modern counterparts. We identify the decade after 1910 as the start of divergence between the physical and crystallographic meaning, catalysed by the discovery of X-ray diffraction and the development of lattice dynamics, although the current definitions did not become entrenched until the 1940s. While history has shown us that this classificatory issue is not just a matter of scientific disagreement and perhaps at its root is a disagreement in our understanding of classification itself. Lastly, we discuss possible resolutions to the matter.

William Barlow’s early publications in the ‘Zeitschrift für Krystallographie und Mineralogie’ and their influence on crystal structure research

Abstract The English crystallographer William Barlow is famous for two achievements, both published in German, in Zeitschrift für Krystallographie und Mineralogie between 1894 and 1901. They concern the derivation of all possible symmetrical arrangements of points in space and the idea to represent crystal structures by replacing points by spheres. His results had an impact upon crystal structure modelling and describing crystal morphology. Utilizing self-made models, he found the 230 space group types of symmetry obtained earlier by both E. S. Fedorow and A. Schoenflies in a different manner. The structures he proposed before the discovery of X-ray diffraction served in some cases as starting point for the interpretation of diffraction patterns thereafter.

Esperienze educative alla mostra "Cristalli ai Raggi X": il gesso di Vezzano sul Crostolo (RE)

The General Assembly of the United Nations declared 2014 the International Year of Crystallography, after 100 years from the awarding of the first Nobel Prize for the discovery of X-ray diffraction by crystals. On this occasion, the Department of Chemical and Geological Sciences of Modena and Reggio Emilia University (Italy)and its Museum “Gemma 1786”, organized an exhibition named Cristalli ai raggi X (Modena, 24 Jan.-29 Mar. 2015). The initiative involved the cooperation of many public and private partners and the active participation of twenty schools of different types and levels. An innovative aspect was the planned participation of highschool students to the fifty collateral events organized during the exhibition. The main purpose of Cristalli ai raggi X was to introduce non-specialists to the world of crystals and their properties, and to show how crystallography plays a role in the development of scientific disciplines. The display ended with the appreciation of 9,000 visitors and a hundred of guided tours for regional and extra-regional schools.The activity developed by the Manini Middle School of Vezzano sul Crostolo (Reggio Emilia province) involved 27 students of 13thyear-old. During an exhibition event opened to the public, they presented a study on the features of gypsum and the extraction history of the land where they come from and where, in the past, the gypsum was an important economic resource.

First Russian Crystallographic Congress: From Convergence of Sciences to Nature-Like Technologies

For the last 100 years, crystallography has passed a complex and interesting way: from descriptive mineralogy; through chemistry, chemical analysis, and new crystal growth technologies; to physics (X-ray diffraction analysis, physical materials science) and then to biology and protein crystallography. Actually, the starting point in the development of modern crystallography is the discovery of X-ray diffraction. Specifically X rays revealed the complex, three-dimensional, and periodic structure of all materials surrounding us.

Who's Who in Mineral Names: Max von Laue and the Discovery of X-ray Diffraction by Crystals (1879–1960)

Laueite, Mn2+Fe23+(PO4)2(OH)2·8H2O, is a common late-stage hydrothermal phosphate mineral found in oxidized triphylite-bearing complex granite pegmatites (Anthony et al. 2000). The mineral was name...

A tale of two garnets: The role of solid solution in the development toward a modern mineralogy

![][1] This article reviews the development of mineralogy as a science by focusing largely on the common silicate garnets of general formula {X3}[Y2](Si3)O12. It tells of important discoveries, analyses, and proposals by various scientists relating to crystallography, crystal structures, isomorphism, and solid solution starting in Europe in the late 1700s. The critical recognition of the importance of ionic size of atoms in determining crystal-chemical properties and solid-solution behavior is emphasized. The two garnet species “pyralspite” and “(u)grandite,” which were considered to represent two independent solid-solution series, were introduced by N.H. Winchell and A.N. Winchell (1927) in their well-known book Elements of Optical Mineralogy . Critical comments on the assumptions behind the classification scheme have been pointed out for at least 50 yr, but it remains in use. There is more, though, behind this garnet classification scheme than just simple terminology. There are a long series of scientific discoveries and advances that are largely forgotten by the broader mineralogical community. They begin, here, with the work of the “father of crystallography,” Rene-Just Hauy, concerning the microscopic nature of crystals around 1780 and include later discoveries and proposals by Mitscherlich, Beudant, Wollaston, and Kopp relating to isomorphism and solid-solution behavior all before 1850. A second key era started with the discovery of X-ray diffraction in 1912 that allowed the atomic structures of crystals and, furthermore, atomic and ion radii to be determined. In terms of isomorphism and solid solution, the proposals and studies of Vegard, Zambonini, Wherry, A.N. Winchell, and the “father of crystal chemistry” Goldschmidt are briefly discussed. The recognition of the sizes of atoms and ions, along with an understanding of chemical bonding behavior in crystals, was critical in the establishment of what can be termed “modern mineralogy,” a quantitative science as it is largely understood today that emerged by the mid-1930s. The silicate garnet system pyrope-almandine-spessartine-grossular-andradite-uvarovite shows extensive homovalent substitutional solid solution over two structural sites and complete compositional variation between “pyralspite species” and “ugrandite species” has been documented. Thus, the prerequisites behind the terms “pyralspite” and “(u)grandite,” as originally formulated and often accepted even today, are incorrect and use of this classification is not recommended. Diffraction determinations of the volumes of garnet end-members and volumes of mixing of garnet solid solutions give physical insight into solid-solution behavior. Today, investigations of local structural and crystal-chemical properties, together with determinations of lattice strain and thermodynamic mixing properties, of silicate solid solutions are leading to an ever more quantitative understanding of mineral behavior from the microscopic to macroscopic level. [1]: /embed/graphic-1.gif

Crystal Clear. The Autobiographies of Sir Lawrence & Lady Bragg. Edited by A. M. Glazer and Patience Thomson. Oxford University Press, 2015. Pp. xx + 427. Hardback. Price GBP 35.00. ISBN 978-0-19-874430-6.

This book celebrates 100 years since the Nobel Prize was awarded to Sir William Lawrence Bragg (WLB) and his father Sir William Henry Bragg (WHB): the first of a long list (at least 25) of Nobel Prizes earned by scientists exploiting Max von Laue’s discovery of X-ray diffraction by crystals in 1912. The prize awarded to the Braggs also established two other records: the youngest Nobel laureate in science and the only case of father and son joint Nobel laureates. I would also like to underline that in those years crystals were for the second time the protagonist of a revolution in solid-state science: the first time was the discovery of double refraction in calcite (E. Bartholinus, 1669, and C. Huygens, 1690), an event that triggered the understanding and exploitation of the anisotropic properties of matter. The book is an original product of Mike Glazer’s longstanding interest in the Braggs, in particular in the younger one, whom he first met as a teenager and later as a PhD student of Dame Kathleen Lonsdale, a former student of WHB. Glazer contacted the heirs of the two Nobel laureates and, among other important documents, obtained the unknown autobiographies, now published. Obviously, Patience Thomson, the younger daughter of WLB, is an exceptional co-editor for the autobiographies of her parents. Following an 11-page-long foreword by Mike Glazer, the book develops through three chapters: Meet Mother and Father (by Patience Thomson), where the younger daughter of WLB briefly reports her earliest memories when she was still living with her parents; in William Lawrence Bragg (In His Own Words) WLB goes through his life from his youth in Australia to the professorship at Cavendish Laboratory, stopping at 1951, shortly before his move to the Royal Institution (1954); finally, in Alice Grace Jenny Bragg ‘The Half Was Not Told’ Lady Bragg writes about her life up to the passing away of WLB in 1971. The book is illustrated by several valuable sketches drawn by a talented WLB, a hobby accompanying and complementing his interest in birdwatching and, more generally, offering a competent observation of nature. In the long list of his visits to universities and laboratories all around the world, WLB always managed to save a few days to explore the countryside, possibly together with his wife with whom he shared a deep love of nature. In comparison to the autobiographies of other famous scientists, that of WLB is to some extent disappointing, at least for those interested in tracing the development of the scientific ideas and achievements of the author. In fact, whereas Max von Laue – to quote a scientist in the field of X-ray crystallography – in his autobiography gives little space to private life but covers in depth the basis for his revolutionary experiment, WLB dedicates about 50% of his autobiography to his family, including the periodic holidays and related hobbies. The scientific aspects and duties of his rich career are reported, but often without going into the background and the details that would be useful for the reader to gain a better understanding of his scientific work. Even less is dedicated to comments on people with whom he had contact, from students and co-workers, up to famous scientists. However, by comparing the husband’s and wife’s autobiographies some new light can be shed on at least three controversial aspects of WLB’s scientific career: his role in solving the first crystal structures, an achievement that earned him and his father the joint ISSN 2053-2733

100 years of crystallography: new dimensions offered by large scale facilities

100 years have passed since the discovery of x-ray diffraction by von Laue, Knipping and Friedrich. The scientific world owes a lot to Rontgen for the discovery of x-rays in 1895 and with the research efforts of W L and W H Bragg in 1912, the concept of Bragg’s law and interpretations given by P P Ewald, saw the birth of the wonderful field of crystallography. Today, the scientific world sees the various tools delivered by this powerful technique as indispensible, whether it concerns the development of advanced high-tech materials or the structural understanding of biological molecules or drug design. Diffraction and associated methods for structure analysis at the atomic scale are developed into powerful fingerprint methods, and have become the backbone of industry for quality inspection on one hand, and on the other hand, stand at the forefront of materials characterization in research laboratory. Beyond these characterization tools available at laboratory level, large scale facilities (LSF) and notably the neutron and synchrotron radiation sources became increasingly important during the last decades. Diffraction with neutron or synchrotron radiation is very complementary, as outlined below: Neutrons have the corresponding wavelengths and energies directly related to interatomic distances and lattice dynamics. Thus, neutron scattering enables simultaneous access to both structure and dynamics of any type of materials. Neutrons also have a magnetic moment allowing direct characterization of the magnetic structure of materials at the microscopic scale. The possibility to easily vary the contrast of a single element using its different isotopes renders the neutron to be an irreplaceable tool in chemistry, solid state physics, biology and soft matter. Then, having no electric charge, neutrons can easily penetrate materials without significant absorption, allowing a nondestructive characterization even on large volume fractions

From X-rays to the h-hypothesis: Sommerfeld and the early quantum theory 1909–1913

Sommerfeld was deeply interested in the nature of X-rays. In 1900 he concluded from diffraction experiments on slits that, if X-rays are electromagnetic radiation, their “impulse width” should be of the order of magnitude of the size of molecules. In 1905 Sommerfeld regarded it “a shame that after ten years after Rontgen’s discovery one still does not know what is going on with X-rays”. When he became Rontgen’s colleague a year later, he perceived this shame even more as a challenge. By that time it was discovered that X-rays come in two varieties. One sort of X-rays was independent of the anti-cathode material and could be explained by Sommerfeld in 1909 as “Bremsstrahlung”, i.e. as an electromagnetic radiation caused by the deceleration of electrons at their impact in the anti-cathode. The other part had the character of a fluorescent radiation. The “Bremsstrahlung” was polarized and displayed an angular distribution of intensity with a characteristic shape dependent on the energy of the electrons at the impact in the anti-cathode; the other part was unpolarized and characteristic for the material of the anti-cathode. Sommerfeld’s “Bremsstrahlen”-theory could not be elaborated without further assumptions about the impact of electrons in the anti-cathode. Sommerfeld closed his theory by a quantum hypothesis: He linked the time required to stop an electron, t, and the energy released in this process, E, to Planck’s quantum of action, h, via tE = h. This so-called h-hypothesis became the subject of Sommerfeld’s presentation at the first Solvay Conference. Although met with criticism, the quantum effort at Munich raised curiosity. Sommerfeld attempted to verify this hypothesis theoretically and experimentally in his institute with Walther Friedrich, his experimental assistant. Friedrich, a doctoral student from Rontgen’s institute, was persuaded however by Max Laue, then Sommerfeld’s Privatdozent, to perform another experiment which led to the discovery of X-ray diffraction in crystals. Their sensational result, obtained in spring 1912, was among the subjects for the second Solvay Conference in 1913. Sommerfeld regarded this experiment the most important achievement of his institute – and silently buried the h-hypothesis which turned out to be one of the dead-ends of the early quantum theory.

Early developments in crystallography

It has been more than 100 years since the discovery of X-ray diffraction by crystals. The evolution of this technique has transformed our understanding of Nature very profoundly. In India, the early proponents of this area of research were Kedareshwar Banerjee, A R Verma, S Ramaseshan and G N Ramachandran, etc. In this article, contributions of some of them are highlighted.

Evolution of diffraction methods for solving crystal structures

The discovery of X-ray diffraction in 1912 by Laue and co-workers had important implications for the physics of diffraction, for the nature of X-radiation and for the structure of matter. Lawrence Bragg made important contributions to early developments in each of these areas, but the most pregnant of his innovations was in structure determination from X-ray diffraction data. He continued to make highly significant contributions to structure determination right on to the first crystal structures of proteins. Crystallography has made substantial contributions to chemistry and biology, and notably so for biological macromolecules.

Diffraction Across the Length Scale

This JOM special topic concerns advances in neutron and x-ray diffraction directed toward the study of the structural properties of materials at different length scales. This year, the scientific community is celebrating 100 years since the discovery of x-ray diffraction by Laue, Bragg, and the first experimental diffraction pattern obtained from a crystal by Friedrich and Knipping. After their experiment, it was immediately understood that x-rays could become one of the most powerful tools for material characterization, medicine, etc. During the last century, the importance of diffraction methods utilizing x-rays and later electrons, neutrons, and Mossbauer photons increased enormously, while their area of applicability significantly broadened. For example, compare the first laboratory x-ray tubes of 100 years ago with the ultrabrilliant synchrotron x-ray sources of today that have opened fantastic possibilities for the analysis of structure in a broad spectrum of materials. In the first decades of x-ray science, the studies of regular Laue–Bragg reflections, specifically their positions and intensities, were the primary focus of research. This allowed the characterization of crystallographic structure starting from simple lattices and moving toward complicated organic structures. Diffraction studies became the basis for the development of crystallography, physics, chemistry, etc. Later, the focus of x-ray science moved to the understanding of both static and dynamic lattice defects. In real crystals, thermal vibrations and other defects disturb periodic atomic arrangements and alter the diffracted intensity. Diffraction lines and reflections may broaden, their intensity weakens, and sometimes the so-called diffuse scattering appears around and between the Bragg peaks. The character of the scattered intensity relates to the shortand long-range order, type, and symmetry of defects, the interaction energy between different atoms, the Fermi surface, and phonons, and critical fluctuations near phase transitions, etc. The selected manuscripts present a slice of several x-ray and neutron diffraction applications that are currently the focus of research in different laboratories worldwide. These manuscripts demonstrate the possibilities of materials studies utilizing small local probes providing information about submicron volumes in those materials and larger beams probing statistically averaged properties of those materials. First, three manuscripts titled ‘‘Microscopic Deformation in Individual Grains in an Advanced High-Strength Steel’’ by Zhenzhen Yu, Roziliya Barabash, Oleg Barabash, Wenjun Liu, and Zhili Feng, ‘‘Acquisition, Sharing and Processing of Large Datasets for Strain Imaging: An Example of an Indented Ni3Al/Mo Composite’’ by N.S. McIntyre, R.I. Barabash, J. Qin, M. Kunz, N. Tamura, and H. Bei and ‘‘In Situ Observation of the Dislocation Structure Evolution During a Strain Path Change in Copper’’ by Christian Wejdemann, Henning Friis Poulsen, Ulrich Lienert, and Wolfgang Pantleon present example applications of different versions of x-ray microdiffraction with a beamsize 0.5 lm for in-depth understanding of the mechanical behavior at the mesoscale. Several versions of microdiffraction were developed: Polychromatic x-ray microdiffraction (PXM) and differential aperture x-ray microscopy (DAXM) were developed by Oak Ridge National Laboratory at the microdiffraction beamline 34-IDE at the Advanced Photon Source at Argonne National Laboratory. This method is directly based on Laue diffraction experiments. Modernization of the beam line apparatus and the high brilliance of synchrotron emissions create unusual opportunities to extract the mesoscale information about the materials. A slightly different version of this technique is described by McIntyre et al. where it is employed at the microdiffraction beamline at the Advanced Light Source. The PXM technique utilizes both a monochromatic beam and a white (pink) beam with an energy range of 5–25 keV. It is best suited to study defects in polycrystalline or multiphase materials Rozaliya I. Barabash is the guest editor for the Mechanical Behavior of Materials Committee of the TMS Structural Materials Division, and coordinated the topic Diffraction Studies across the Length Scales in this issue. JOM, Vol. 65, No. 1, 2013

The discovery of X-ray diffraction

Starting from the discovery of Roentgen’s X-ray (Rontgen 1895), I here reconstruct the various attempts carried out to find X-ray diffraction using very thin wedge-shaped slits. These experiments allowed A. Sommerfeld to achieve, at the beginning of 1912, a qualitative estimate of the wavelength of X-rays around 4 × 10−9 cm. This value was at the base, together with the adoption of the space-lattice model for the crystal, of Laue idea of using a crystal as a diffraction grating for X-ray. Then we will discuss the feasibility of the Laue project, as well as the realization of the experiment, and the first results of W. Friedrich and P. Knipping, with the theoretical interpretation given to them by Laue. Laue’s discovery of X-ray diffraction was immediately taken up by William Henry Bragg and re-interpreted by his son William Lawrence in terms of X-ray reflection by the planes of the crystal, thus becoming, in a few months, a formidable tool for the study of crystal structures, as well as for the precise determination of the wavelengths of X-rays (to Bragg father we owe the construction of the first X-ray ionization spectrometer). Particular attention will be given to the works of C. G. Barkla on X-ray absorption, which resulted in the discovery in 1906 of the Roentgen characteristic radiation of the elements. These works strengthened the hypothesis of the wave nature of X-rays, at the expense of the “corpuscular hypothesis” (supported notably by J. Stark and by W.H. Bragg), and represented a solid reference point for the project of Laue.

The 100th anniversary of the discovery of X-ray diffraction

A general historical essay on studies related to the discovery of X-ray diffraction, beginning with the first works by W.C. Roentgen, W. Friedrich, P. Knipping, and M. Laue, is presented. The coming of age of X-ray diffraction as an efficient tool for determining crystal structure is considered. The pioneering studies by W.G. Bragg, W.L. Bragg, Yu.V. Wulf, and E.C. Fedorov are briefly reviewed. The contribution of the Russian scientific school to the development of X-ray studies is indicated. The modern state and the directions of development of X-ray physics are discussed.

Max von Laue and the discovery of X‐ray diffraction in 1912

From today’s perspective, only a few discoveries are regarded to be as exciting and as ground-breaking as the discovery of X-ray diffraction by crystals. “The undersigned are engaged since 21 April 1912 with experiments about the interference of X-rays passing through crystals,” a one-page report announced the discovery to the Bavarian Academy of Science. It was signed by Walter Friedrich, Paul Knipping and Max Laue (then still without the “von”) and deposited by Arnold Sommerfeld on 4 May 1912 in order to ascertain the discovery before it was officially communicated in the form of an elaborate paper. “The guiding idea was that interferences arise in consequence of the space lattice structure of the crystals, because the lattice constants are ca. 10 times greater than the conjectured wavelengths of the X-rays.” A simple drawing sketched the experimental arrangement. As evidence for the discovery some exposures were attached.1

Disputed discovery: The beginnings of X-ray diffraction in crystals in 1912 and its repercussions

The discovery of X-ray diffraction is reviewed from the perspective of the contemporary knowledge in 1912 about the nature of X-rays. Laue‘s inspiration that led to the experiments by Friedrich and Knipping in Sommerfeld‘s institute was based on erroneous expectations. The ensuing discoveries of the Braggs clarified the phenomenon (although they, too, emerged from dubious assumptions about the nature of X-rays). The early misapprehensions had no impact on the Nobel Prizes to Laue in 1914 and the Braggs in 1915; but when the prizes were finally awarded after the war, the circumstances of ‘Laue‘s discovery’ gave rise to repercussions. Many years later, they resulted in a dispute about the ‘myths of origins’ of the community of crystallographers.

Disputed discovery: the beginnings of X-ray diffraction in crystals in 1912 and its repercussionsThis Laue centennial article has also been published inZeitschrift für Kristallographie[Eckert (2012).Z. Kristallogr.227, 27–35

The discovery of X-ray diffraction is reviewed from the perspective of the contemporary knowledge in 1912 about the nature of X-rays. Laue's inspiration that led to the experiments by Friedrich and Knipping in Sommerfeld's institute was based on erroneous expectations. The ensuing discoveries of the Braggs clarified the phenomenon (although they, too, emerged from dubious assumptions about the nature of X-rays). The early misapprehensions had no impact on the Nobel Prizes to Laue in 1914 and the Braggs in 1915; but when the prizes were finally awarded after the war, the circumstances of `Laue's discovery' gave rise to repercussions. Many years later, they resulted in a dispute about the `myths of origins' of the community of crystallographers.

Max von laue’s role in the relativity revolution

Whereas countless studies have been devoted to Einstein’s work on relativity, the contributions of several other major protagonists have received comparatively little attention. Within the immediate German context, no single figure played a more important role in developing the consequences of the special theory of relativity (SR) than Max von Laue (1879–1960). Although remembered today mainly for his discovery of x-ray diffraction in 1912 – an achievement for which he was awarded the Nobel Prize – Laue’s accomplishments in promoting the theory of relativity were of crucial importance. They began early, well before most physicists even knew anything about a mysterious Swiss theoretician named Einstein (Fig. 19.1).

X-ray film as a two-dimensional detector for X-ray diffraction analysis

Silver halide based photographic imaging elements have been utilized as detectors for X-rays for over 100 years. These elements comprised of gelatin dispersed silver halide coated on one or both sides of a support, have been utilized in diffraction experiments since the discovery of X-ray diffraction by Laue and co-workers. X-ray film has high spatial resolution and can be adapted to flat or curved two-dimensional detection geometries. This paper describes the use of X-ray film as a two-dimensional detector for X-ray diffraction analysis, and discusses X-ray film composition, exposure, and processing, along with considerations for analyzing X-ray diffraction data collected using X-ray film.

Crystallography of Modulated Structures in Superspace

Since the discovery of X-ray diffraction, it was believed that the discrete distribution of diffracted intensities was a direct consequence of the periodic arrangement of atoms in the three dimensions of space. However, in the last thirty years many examples of new types of crystals have been found which do not fulfil this criterion but nevertheless give perfectly discrete diffraction patterns. The new category of crystals which exhibits this property is called aperiodic. It includes incommensurate crystals, quasicrystals and composite crystals. These structures are best described in superspace, an extension of the three-dimensional space up to six dimensions. Aperiodic structures can be interpreted as three-dimensional cuts of higher dimensional periodic objects. The description of an incommensurate structure in 3+1 dimensions along with the concept of symmetry in superspace is presented as an example.