A Direct Approach to Crystal Structure Determination - a solution to the phase problem. The purpose of this research is to determine the positions of atoms in crystals and nano-crystals. We have developed a theory that shows how to extract all of the information required to determine atomic positions from such crystals and we have carried through initial successful tests on simple materials. In particular, we have found that crystallographic phase, hitherto not directly measurable, can in fact b ....A Direct Approach to Crystal Structure Determination - a solution to the phase problem. The purpose of this research is to determine the positions of atoms in crystals and nano-crystals. We have developed a theory that shows how to extract all of the information required to determine atomic positions from such crystals and we have carried through initial successful tests on simple materials. In particular, we have found that crystallographic phase, hitherto not directly measurable, can in fact be extracted uniquely from a single electron diffraction pattern. This constitutes a solution to the phase problem in crystallography. It is now our aim to develop this method into a routine technique.Read moreRead less
Grain-boundary sliding in high-temperature ceramics: mechanical spectroscopy of high-purity magnesium oxide. The demise of elastic behaviour in materials stressed at sufficiently high temperature limits the usefulness of ceramics for structural applications, and is also responsible for reduced wave speeds and associated attenuation of seismic waves in the Earth's interior. Yet the nature of the transition in fine-grained materials tested at high temperature from elastic through anelastic to vis ....Grain-boundary sliding in high-temperature ceramics: mechanical spectroscopy of high-purity magnesium oxide. The demise of elastic behaviour in materials stressed at sufficiently high temperature limits the usefulness of ceramics for structural applications, and is also responsible for reduced wave speeds and associated attenuation of seismic waves in the Earth's interior. Yet the nature of the transition in fine-grained materials tested at high temperature from elastic through anelastic to viscous rheology remains poorly understood. Through a combination of mechanical testing by torsional forced oscillation/ microcreep methods of carefully fabricated and characterised specimens of polycrystalline MgO and associated micro-mechanical modelling we seek to clarify this fundamental and general aspect of high-temperature mechanical behaviour.Read moreRead less
Mineral Physics of the Earth's Core. Most information on the nature of Earth's core properties has come from teleseismic studies, which detect weak earthquake-wave signals that have traversed the Earth's deepest interior. These studies have revealed several unusual and enigmatic phenomena in the core, but interpretation of these observations must rely on mineral-physics data on the materials of the core (e.g. iron-based alloys). This project will create a unique world-class ultra-high pressure l ....Mineral Physics of the Earth's Core. Most information on the nature of Earth's core properties has come from teleseismic studies, which detect weak earthquake-wave signals that have traversed the Earth's deepest interior. These studies have revealed several unusual and enigmatic phenomena in the core, but interpretation of these observations must rely on mineral-physics data on the materials of the core (e.g. iron-based alloys). This project will create a unique world-class ultra-high pressure laboratory to obtain such data. By defining the composition and mineralogy of Earth's core, it will place Australia in the forefront of this exciting research field, and will also represent a major national resource for the study of novel materials at extreme conditions.Read moreRead less
UNDERSTANDING PHASE TRANSITIONS THROUGH PRECISE STRUCTURAL STUDIES. This project will examine the fundamental nature of the structural phase transitions that are critical for the utilisation of numerous advanced materials. Researchers at Sydney University and the Australian National University in collaboration with staff at ANSTO are world leaders in the structural analysis of such materials. Through comprehensive experimental and theoretical studies of a number of such materials this project w ....UNDERSTANDING PHASE TRANSITIONS THROUGH PRECISE STRUCTURAL STUDIES. This project will examine the fundamental nature of the structural phase transitions that are critical for the utilisation of numerous advanced materials. Researchers at Sydney University and the Australian National University in collaboration with staff at ANSTO are world leaders in the structural analysis of such materials. Through comprehensive experimental and theoretical studies of a number of such materials this project will enhance the ability of industry to develop new and improved materials.Read moreRead less
Platinum-group Metal Oxides with Modulated Crystal Structures: Flexible Frameworks Designed for Geometrically Frustrated Magnetism. Magnetic materials are of huge importance to modern society because of the key roles they play in devices such as hard disks, sensors, switches and permanent magnets. This project will focus on the chemical design and synthesis of novel, flexible and unconventional magnetic materials. Their study will lead to improved theories of magnetism and superconductivity, and ....Platinum-group Metal Oxides with Modulated Crystal Structures: Flexible Frameworks Designed for Geometrically Frustrated Magnetism. Magnetic materials are of huge importance to modern society because of the key roles they play in devices such as hard disks, sensors, switches and permanent magnets. This project will focus on the chemical design and synthesis of novel, flexible and unconventional magnetic materials. Their study will lead to improved theories of magnetism and superconductivity, and ultimately to technologies such as new data-storage media. The project will also help introduce Australian scientists to their new research reactor and synchrotron, which will play critical roles by allowing exceptionally thorough and systematic studies to be carried out.Read moreRead less
Learning to predict polymorphism through simulation of nucleation and nanoparticle evolution. Many substances are capable of exhibiting a myriad of different structures despite having the same composition. This behaviour can have a significant impact on the production of new pharmaceuticals, since the sudden appearance of a new form can lead to instant withdrawal of the drug. By understanding how different forms grow, rather than focusing on just the stability of the product, this research will ....Learning to predict polymorphism through simulation of nucleation and nanoparticle evolution. Many substances are capable of exhibiting a myriad of different structures despite having the same composition. This behaviour can have a significant impact on the production of new pharmaceuticals, since the sudden appearance of a new form can lead to instant withdrawal of the drug. By understanding how different forms grow, rather than focusing on just the stability of the product, this research will lead to more reliable prediction of how pharmaceutical molecules might assemble. The same technology will potentially have impacts in many areas of nanoscience through improvements in efficiency, including the production of minerals, desalination and undersea gas recovery.Read moreRead less
An experimental study of trace element equilibria during metamorphism. The analytical methods and experimental data to be developed will enable an Australian team to become world leaders in determining pressures and temperatures of mineral growth that correspond to a range of depths and temperature gradients in the Earth tha t is wider than accessible previously. Obtaining this information from small zones within single grains will allow determination of rates of change, and give us a detailed p ....An experimental study of trace element equilibria during metamorphism. The analytical methods and experimental data to be developed will enable an Australian team to become world leaders in determining pressures and temperatures of mineral growth that correspond to a range of depths and temperature gradients in the Earth tha t is wider than accessible previously. Obtaining this information from small zones within single grains will allow determination of rates of change, and give us a detailed picture of how the host rock has evolved, even from very small samples. One application would be checking the origin of relatively common minerals for whether they could be associated with diamonds.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE100100236
Funder
Australian Research Council
Funding Amount
$180,000.00
Summary
Facilities for spectroscopy and diffraction at high pressures. The provision of infrastructure for the study of novel materials under high pressures will enhance Australia's capability in creating new materials and in creating new devices that meet needs in communication, environment and medicine applications. The new facility will enable researchers to understand the response of structures to extreme pressures and will exploit the unique capabilities of the synchrotron light.