Crystals

Crystal (584)
Crystal structure (53)
Crystallography (69)
Silica (101)
Snowflake (8)

Synopsis: Materials: Classes of materials: Crystals:

in order to fabricate ultra-sensitive sensors via the production of calcium phosphate crystals. By adding antibodies to this process,

Once the crystals are formed, their development and recognition actions can be detected by electrodes. The presence of the crystals on the electrodes is detected as the signal of the bioassay which,

for scientists, is a way of studying or picking up the signs of cell change:

Dr de la Rica made the decision to grow metal nanocrystals rather than the traditional calcium phosphate crystals as a way to generate a signal.

These intensely coloured crystals possess outstanding optical properties and provide signals which are clearly readable or visible with standard lab instruments and even the naked eye.

to grow the crystals. This meant the sensor design would be simplified further.""There is also no need for the electrodes

#3, 600 crystals in wearable skin monitor health 24/7 A new wearable medical device that uses up to 3600 liquid crystals can quickly let you know

This crystal structure creates a more robust edge and the more edge the better for catalytic reactions

At present researchers usually rely on X-ray crystallography to investigate protein structures. This requires growing crystals consisting of billions of identical molecules.

Crystallizing proteins is challenging and sometimes impossible researchers say. If the ETH physicists achieve their goal a single molecule would in principle suffice for determining the structure.

and larger colloidal crystals at temperatures ranging from room temperature to 85 degrees C. At room temperature the polymers act as a gas bumping against the larger particles

In fact the colloids form a crystal using this process known as the depletion interaction#an attractive entropic force

As usual the crystals melt on heating but unexpectedly on heating further they re-solidify. The solid is much softer more pliable

and more open than the crystal. This result the researchers observe reflects enthalpic attraction#the adhesive energy generated by the higher temperatures and stimulating bonding between the particles.

and a Raman gain in silica despite increasing loss. ight intensity is a very important parameter in optical systems

The experimental system that the researchers used consists of two tiny directly coupled silica microtoroid (doughnut-shaped) resonators each coupled to a different fiber-taper coupler that aids in guiding light from a laser diode to photodetectors;

Loss is delivered to one of the microresonators by a tiny device a chromium-coated silica nanotip

#3, 600 crystals in wearable skin monitor health 24/7 A new wearable medical device that uses up to 3600 liquid crystals can quickly let you know

and matter interact at the surface of a silver crystal. They observe for the first time an exciton in a metal.

and Petek and his team experimentally discovered that the surface electrons of silver crystals can maintain the excitonic state more than 100 times longer than the bulk metal enabling the excitons in metals to be captured experimentally by a newly developed multidimensional coherent spectroscopic technique.

#Renewable cellulose crystals are as stiff as steel The same tiny cellulose crystals that give trees

Calculations using precise models based on the atomic structure of cellulose show the crystals have a stiffness of 206 gigapascals

are detailed in the journal Cellulose. t is very difficult to measure the properties of these crystals experimentally

and predict the behavior of individual crystals the interaction between them and their interaction with other materialszavattieri says. his is important for the design of novel cellulose-based materials as other research groups are considering them for a huge variety of applications ranging from electronics

another process to use the leftover cellulose to make a composite materialmoon says. he cellulose crystals are more difficult to break down into sugars to make liquid fuel.

#DNA helps nanoparticle crystals self-assemble Northwestern University rightoriginal Studyposted by Megan Fellman-Northwestern on December 2 2013using the same structure found in nature researchers have built the first near-perfect single crystals

and DNA. ingle crystals are the backbone of many things we rely onâ##diamonds for beauty as well as industrial applications sapphires for lasers

and silicon for electronicssays nanoscientist Chad A. Mirkin. he precise placement of atoms within a well-defined lattice defines these high-quality crystals. ow we can do the same with nanomaterials

research group developed the ecipefor using nanomaterials as atoms DNA as bonds and a little heat to form tiny crystals.

This single-crystal recipe builds on superlattice techniques Mirkin s lab has been developing for nearly two decades.

and shape of crystals they can build. The team worked with gold nanoparticles but the recipe can be applied to a variety of materials with potential applications in the fields of materials science photonics electronics

and catalysis. A single crystal has order: its crystal lattice is continuous and unbroken throughout. The absence of defects in the material can give these crystals unique mechanical optical and electrical properties making them very desirable.

In the study strands of COMPLEMENTARY DNA act as bonds between disordered gold nanoparticles transforming them into an orderly crystal.

We are learning so many rules for calculating things that other people cannot compute in atoms in atomic crystals. he ratio affects the energy of the faces of the crystals

and result in a sphere not a faceted crystal she explained. With the correct ratio the energies fluctuate less

and result in a crystal every time. magine having a million balls of two colors some red some blue in a container

and link togetherhe says. hey beautifully assemble into a three-dimensional crystal that we predicted computationally

and realized experimentally. o achieve a self-assembling single crystal in the lab the research team reports taking two sets of gold nanoparticles outfitted with COMPLEMENTARY DNA

The very slow cooling process encouraged the single stranded-dna DNA to find its complement resulting in a high-quality single crystal approximately three microns wide. he process gives the system enough time

There s no reason we can t grow extraordinarily large single crystals in the future using modifications of our techniquesays Mirkin who also is a professor of medicine chemical and biological engineering biomedical engineering and materials science and engineering and director of the university s International Institute for Nanotechnology.

#Crystal structure could push the limits of solar cells University of Pennsylvania right Original Studyposted by Evan Lerner-Pennsylvania on November 13 2013 A new model for solar cell construction may ultimately make them less expensive easier to manufacture

The resulting crystal would ideally have the structure of the parent but with elements from the second material in key locations enabling it to absorb visible light. he design challengesays Peter K. Davies chair of the department of materials science and engineering as to identify materials that could retain their polar properties while simultaneously absorbing visible light.

Most light absorbing materials have a symmetrical crystal structure meaning their atoms are arranged in repeating patterns up down left right front and back.

A perovskite crystal has the same cubic lattice of metal atoms but inside of each cube is an octahedron of oxygen atoms

It's not something we had to architect ourselves. fter several failed attempts to physically produce the specific perovskite crystals they had theorized the researchers succeeded with a combination of potassium niobate the parent polar material and barium nickel niobate

The researchers used X-ray crystallography and Raman scattering spectroscopy to ensure they had produced the crystal structure and symmetry they intended.

Until recently the preparation of phosphor materials was more an art than a science based on finding crystal structures that act as hosts to activator ions

The researchers were able to stabilize the light s frequency by developing a silica glass chip resonator with a specially designed path for the photons in the shape of

In addition to its use as a frequency reference for lasers a reference cavity could one day play a role equivalent to that of the ubiquitous quartz crystal in electronics.

##and manmade products constructed from similar materials has to do with the hierarchical architecture of the biological materialsâ##the way the silica-based skeletons are built up from different structural elements some

For the purposes of this experiment the researchers placed silica##manganese oxide eadson the matchstick material and introduced hydrogen peroxide as the chemical fuel in one particular place.

or mechanical peeling, from a crystal of graphite. But exfoliation is a time-consuming process that will never be practical for any of the many potential applications of graphene that require industrial mass production. httpv://www. youtube. com/watch?

is about 90 percent as strong as the ideal crystal. his is an exciting result for the future of graphene,

Products that use silica-based nanoparticles for biomedical uses such as various chips drug or gene delivery and tracking imaging ultrasound therapy and diagnostics may also pose an increased cardiovascular

and interaction of silica-based nanoparticles with biological systems write the researchers. Because our research demonstrates a clear cardiovascular health risk associated with this trend steps need to be taken to help ensure that potential health

For when heated, vanadium dioxide s crystals begin to rapidly contract along one dimension, while expanding along the other two,

or tiny crystals that exhibit quantum mechanical properties. The cells were further able to communicate with each other

The physicists used special nonlinear crystals to achieve the superposition of the photons'polarization states,

Both teams made diamonds with defects in their crystal structure#a single nitrogen atom next to a missing carbon atom, a few nanometres below the surface.

The idea would be to place a diamond crystal onto the tip of a scanning microscope,

As such, a polycrystal made of nanotwin domains is a bit like a slab of plywood where the wood grain reverses direction in each successive layer.

In the boron nitride polycrystals synthesized by Tian and his colleagues, the nanotwin segments are just 3. 8 nanometers wide on average.

contain numerous defects where crystals can nucleate under high temperature and pressure but resist rapid crystal growth,

Quantum dots are crystals about 10 nano#metres in diameter, made from a semiconductor material, commonly cadmium selenide.

#Taking the crystals out of X-ray crystallography The technique that revealed DNA's double helix

A method described in Nature this week1 makes X-ray crystallography of small molecules simpler, faster and more sensitive,

largely doing away with the laborious task of coaxing molecules to form crystals. Instead, porous scaffolding holds molecules in the orderly arrangement needed to discern their structure with X-rays.

You could call it crystal-free crystallography, says Jon Clardy, a biological chemist at Harvard Medical school in Boston,

X-ray crystallography is one of the most important techniques in science, because it is one of only a few ways to directly determine the shape of large molecules.

Clardy says, the biggest bottleneck in X-ray crystallography.""Some crystallize easily, some crystallize hardly and some are impossible to crystallize,

"Our next grand challenge is to apply this method to protein crystallography, he says

#Synthetic vaccine could prevent future outbreaks of foot-and-mouth disease Virologists have devised a way to create an entirely synthetic vaccine for foot-and-mouth disease.

2."Before this there was no crystal structure for any serotonin receptor. A lot of what was theoretical is known now with a great degree of certainty,

Roth and his colleagues uncovered the receptor structures using X-ray crystallography in which X-ray beams are fired at crystals of the compound,

and the structure is deduced from how the beams scatter. The teams focused on two receptors, called 1b and 2b.

researchers made extremely small perforations in a structure made of two thin films of silver separated by a film of silica.

Artists Discover 3-D Printingthe Missouri S&t team believes the mechanical coloring on the silver/silica materials provide a much higher printing resolution than conventional color printing, according to Gizmag.

The technique incorporates some nickel atoms into the diamond crystal structure, forming what is called an 3 defect center.

but are rich in carbon rather than silica and may contain large layers of diamond. His team reported on models of such a world dubbed 55 Cancri e in October 2012.

Analysing its microscopic crystals Birger Schmitz at Lund University and his colleagues found that the rock dates to the same time period

Cockell's team found that the altered crystal structure of the rocks absorbed and reflected UV rays.

Snowflakes shorelines and most recently black holes (see Turbulent black holes grow fractal skins as they feed) also exhibit such fractal behaviour.

A silica coating on the particles allows additional molecules to attach causing the particles to bind with specific structures within the cell.

Silica makes it completely flexible; it s a well developed material that can bind to almost anything Bawendi says.

Those crystals interfere with the normal magnetic spins of hydrogen atoms. When exposed to a powerful magnetic field hydrogen atoms align their spins in the same direction.

Tracking infectionhemozoin crystals are produced in all four stages of malaria infection including the earliest stages

and fiber that first transfer energy from diode lasers into a medium usually a crystal before converting it into a laser beam.

The material forms tiny crystals a chemically ordered state but with intrinsic randomness such that the orientations of the stacked molecules can be arbitrary

and the sizes of the crystals different, forming aggregate structures that are disordered highly. That combination of order and disorder contributes to eumelanin broadband absorption, the team found. t a naturally existing nanocomposite,

This is the first direct observation of exciton diffusion processes Bulovic says showing that crystal structure can dramatically affect the diffusion process.

While these experiments were carried out using a material called tetracene a well-studied archetype of a molecular crystal the researchers say that the method should be applicable to almost any crystalline or thin-film material.

These crystals are doped with elements such as ytterbium, gadolinium, erbium, and thulium, which emit visible colors

the researchers can tune the crystals to emit any color in the visible spectrum. To manufacture the particles, the researchers used stop-flow lithography,

and films studded with quantum dots or tiny crystals that exhibit quantum mechanical properties. They also engineered the cells

They demonstrated the existence of a quantum-mechanical mixture of electrons and photons, known as a Floquet-Bloch state, in a crystalline solid.

electrons move in a crystal in a regular, repeating pattern dictated by the periodic structure of the crystal lattice.

an ion crystal essentially, a grid of charged atoms in order to study friction effects, atom by atom.

To generate the ion crystal, the group used light to ionize, or charge, neutral ytterbium atoms emerging from a small heated oven,

and pull the ion crystal across the lattice, as well as to stretch and squeeze the ion crystal,

much like an accordion, altering the spacing between its atoms. An earthquake and a caterpillarin general, the researchers found that

when atoms in the ion crystal were spaced regularly, at intervals that matched the spacing of the optical lattice, the two surfaces experienced maximum friction,

when the ion crystal as a whole is dragged across the optical lattice, the atoms first tend to stick in the lattice troughs,

If enough force is applied, the ion crystal suddenly slips, as the atoms collectively jump to the next trough. t like an earthquake,

and squeeze the ion crystal to manipulate the arrangement of atoms, and discovered that if the atom spacing is mismatched from that of the optical lattice,

the crystal tends not to stick then suddenly slip, but to move fluidly across the optical lattice,

as the ion crystal is pulled across the optical lattice, one atom may slide down a peak a bit,

Products that use silica-based nanoparticles for biomedical uses such as various chips drug or gene delivery and tracking imaging ultrasound therapy and diagnostics may also pose an increased cardiovascular

This reality leads to increased human exposure and interaction of silica-based nanoparticles with biological systems.

The researchers used tiny crystals called quantum dots to create the LEDS that generated the colored light.

#Atomic'mismatch'creates nano'dumbbells'Like snowflakes nanoparticles come in a wide variety of shapes and sizes.

Despite the pessimistic prognosis the researchers found that protons pass through the ultra-thin crystals surprisingly easily especially at elevated temperatures

because the pores are too small for optical microscopy and too flexible and mobile for X-ray crystallography."

This crystal structure creates a more robust edge and the more edge the better for catalytic reactions

and revealed the widespread transition from one crystal structure to another. The team also measured the amount of oxygen

their crystal structure is influenced not by the process. The UT scientists present their#findings in the journal Advanced Functional Materials.

because other patterning techniques have the risk of damaging the crystal structure and orientation and thus influence the properties of the material.

"Our study focused on a variety of crystals that have controlled differences in thermal transport properties, such as Si, doped Si,

"We coated these crystals with a thin metal film, heated the surface with a laser beam,

"On length-scales shorter than the phonon mean-free-paths of the crystal, heat is transported ballistically, not diffusively.

when the radius of the laser beam used to heat the metal coated crystals was above ten microns,

predicts that a cubic crystal like silicon will carry heat equally well in all directions.

In particularly for crystals with defects, the boundary resistance is distributed and strongly dependent on the defect concentration."

and packing at electrode surfaces the team combined knowledge about graphene and organic crystals. Though it was difficult Briseno says they managed to get the necessary compounds to stack like coins.

when an undergraduate chose the wrong substrate to grow crystals on. For over a week the student was growing vertical crystals

and we didn't even realize until we imaged the surface of the substrate with a scanning electron microscope.

We were shocked to see little crystals standing upright! We ultimately optimized the conditions and determined the mechanism of crystallization the polymer chemist adds.

Another potential application comes from the fact that silicon crystals at dimensions of 5 nanometers

or crystals of the aluminum matrix that recrystallized after being plasticized were extremely small; smaller aluminum matrix grains can flow past each other more smoothly than larger particles enhancing the strength of the material.

Doping is the process of introducing different atoms into the crystal structure of a material, and it affects how easily electrons can move through ithat is,

"The occupancy of the orbitals and the ability of electrons to move in the crystal are tied very closely togetherr'correlated.'

and negative charges across different regions of the semiconductor crystal thereby creating the basic structure allowing the development of many components used in the semiconductor industry.

because it uses inert gold#silica SERS nanoparticles and a hand-held Raman scanner that can guide brain tumor resection in the operating room o

and deposited as single-layer crystals in the shape of triangles. After a while, evaporated atoms from the second material then attached to the edges of the triangle to create a seamless semiconducting heterojunction."

On a small scale, it takes about five minutes to grow the crystals, with up to two hours of heating and cooling time."

In contrast to other dichroic effects produced by some crystals, such as precious opals, the colorful effects of the Lycurgus cup have little dependence on the position of the observer.

In fact, the dichroism found in the Lycurgus cup has a different origin than crystals and so far this'plasmonic effect'has not been observed in naturally occurring materials."

The'seeds'are multiple crystals of elongated gold decahedrons, joined together by shared facesn arrangement known as multiply-twinning.

"Quite often, two-dimensional crystals have electronic properties that are completely different from those of thicker layers of the same material,

made of silica and nickel, is only 70 nm in diameter; the entire propeller is 400 nm long.

and characterize inkjet printed 2d crystal-based flexible photodetectors and study their integration with commercial electronics.

Graphene the ultimate thin membrane along with a wide range of two-dimensional (2d)- crystals (e g. hexagonal Boron nitride (h-BN) Molybdenum Disulfide (Mos2) and Tungsten Disulfide (WS2)) have changed radically the landscape

These 2d crystals can be exfoliated from layered compounds. The layered compounds can be conductive semiconducting

and the team at the Cambridge Graphene Centre have been looking to formulate a set of inks based on various 2d crystals setting a new platform for printed electronics.

When light impinges on a semiconducting 2d crystal (e g. Mos2) due to their 2d nature electrons and holes are generated with a higher efficiency than the current photodetectors based on siliconthe project funded by the National Natural science Foundation of China looks into how to design printed flexible photodetectors

#A crystal wedding in the nanocosmos Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the Vienna University of Technology and the Maria Curie-Sklodowska University Lublin have succeeded in embedding nearly perfect semiconductor crystals

they integrated compound semiconductor crystals made of indium arsenide (Inas) into silicon nanowires, which are suited ideally for constructing increasingly compact chips.

This integration of crystals was the greatest obstacle for such"hetero-nanowires"until now: beyond the nanometer range, crystal lattice mismatch always led to numerous defects.

and embedding of the Inas crystals into the nanowires for the first time. Implanted atoms form crystals in the liquid-Phase in order to carry out this process,

ion beam synthesis and heat treatment with xenon flash-lamps were used, two technologies in which the Ion beam Center of the HZDR has held experience for many years.

"while the implanted atoms form the indium arsenide crystals.""Dr. Wolfgang Skorupa, the head of the research group adds:"

"The atoms diffuse in the liquid-silicon-phase so rapidly that within milliseconds they form flawless mono-crystals delineated from their surroundings with nearly perfect interfaces."

and also optimize the size and distribution of the crystals a

#Tiny laser sensor heightens bomb detection sensitivity New technology under development at the University of California,

observed for the first time how an electrical current flows across the skin of a silicon crystal and also measured electrical resistance as the current moved over a single atomic step.

Wolkow says silicon crystals are mostly smooth except for these atomic staircaseslight imperfections with each step being one atom high.

For example, experiments have shown that film made of packed nanowires has properties that differ quite a bit from a crystal thin film."

tubular silica template, starting from commercially available, but nonporous fibers. This template is filled then with a special mixture of carbon, silicon dioxide and surfactants,

and consequently are able to maintain their crystal structure during the chemical vapor deposition (CVD) process,

At Caltech the researchers used a process called atomic layer deposition to form a layer of titanium dioxide (Tio2) material found in white paint and many toothpastes and sunscreensn single crystals of silicon gallium arsenide

"Silica-gold nanoparticles provide greater contrast, visibility To get around this, Mr Duczynski used silica nanoparticles coated with a gold shell (silica-gold core-shell nanoparticles) in his research."

"There are some theoretical and experimental papers where it was observed that by varying the dimensions of either the silica core

or gold shell you could also vary the scattering ratio of the particles, "he says."

"Ultraviolet spectroscopy was used on the silica-gold core-shell nanoparticles made by Mr Duczynski to better understand their optical properties, such as extinction, scattering and absorption.

I was having difficulty with shelling the silica particles, "Mr Duczynski says.""I was able to see some scattering of the iron oxide-gold core-shell nanoparticles,

Typically researchers examine zeolite growth by removing crystals from the natural synthesis environment and analyzing changes in their physical properties said Rimer Ernest J. and Barbara M. Henley Assistant professor of Chemical and Biomolecular engineering at UH.

And while most crystals grow through classical means the addition of atoms or molecules to the crystal the presence and gradual consumption of nanoparticles suggested a nonclassical pathway for zeolite crystallization.

Rimer and Lupulescu found that both classical and nonclassical growth models were at work. We have shown that a complex set of dynamics takes place Rimer said.

and low-yield type materials (they used an inert crystal and polymer material to simulate a live explosive in the lab)

The shirts are woven with a hydrophobic silica also known as silicon dioxide. Self Cleaning Clothing With Hydrophobic Nanotechnology as the Kickstarter says might be a vague enough claim to cause some concern

Once that coat dries (about 20 minutes) they apply an acetone solution with small amounts of silica and other proprietary additives.

or snowflakes seem to disappear from its beam to clear the vision of the driver a trick that this team of engineers from Carnegie mellon University has been working on for a few years now.

Self-assembly of this kind can be found in nature#from molecules forming regular crystals

growing germanium crystals on amorphous substances at temperatures low enough for fabricating electronics as well. Such approaches, focused on the long term, will achieve monolithic integration for chips with an electronic front end with optics embedded in the back end

#Crystal breeding factory uncovered A breakthrough in understanding the way in which crystals develop will have a major impact for the pharmaceutical, chemical and food industries.

Lancaster University chemists in collaboration with international colleagues have uncovered a'Crystal Nuclei Breeding Factory'which, they say,

"Crystal'seeds'(very small crystals) are added to the process to act as a'template'to ensure more of the same shape

and size of crystals are produced.""""The rule of the garden isf you sow a single seed you should get a single plant.

However with crystals, a single seed causes thousands of new crystals to form, almost as if'breeding'is taking place.

Fluids, used in the process, shear the weakly tethered new crystals from the seed crystal surface allowing the surfaces to be further available for a repeat process

and the new crystals to go on to act as seed crystals themselves.""This is a big step forward,

size and type of crystals to design.""For some drugs, having the correct'handedness'is essential as you need the right key in the lock to make the drugs work.

Current ideas are that molecules of one of the mirror images came together and led to a chance formation of a mirror crystal which, subsequently, induced massive crystallisation of the same image."

"Thanks to this study, we now know how such a single crystal seed could have amplified its effect

and given rise to thousands of new crystals of the same image,"adds Professor Anwar A

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