X-ray crystallography encompasses the structural characterization of crystalline materials by means of X-rays. This is done most commonly by X-ray diffraction, which can be applied to monocrystalline materials or heterostructures, as well as to polycrystalline materials, where the later is referred ...

learn more… | top users | synonyms

0
votes
2answers
75 views

Reciprocal Lattice in Crystallography

How do you get the reciprocal lattice vectors? No, I'm not talking about the formula's. I mean to ask where do the formula's even come from? I could not find a clear derivation of the reciprocal ...
0
votes
2answers
303 views

Bragg diffraction and lattice planes

Crystalline substances show, for certain sharply defined wavelength and incident directions, very sharp peaks of scattered X-ray radiation. From the illustration below we see that we get constructive ...
-1
votes
2answers
234 views

Compute distance between planes in a crystal

I want to compute the distance between two (111) planes in a cubic crystalline structure, in order to do some computations involving Bragg reflection. I have a sketch of which the (111) planes are, ...
2
votes
1answer
78 views

Are the 14 Bravais lattices really distinct?

I have learned that there are 14 distinct Bravais lattices in 3D and any other thought lattice form could be reduced to or expressed in one of these 14 forms. But the primitive unit cell for f.c.c ...
1
vote
1answer
52 views

X-ray diffraction analyisis: The angle of elastic x-ray scattering

What is the scattering angle distribution for x-rays (in the 8keV range) scattered elastically? I work with XRD analysis, which is fundamentally basede on these elastic scatterings of x-rays. I read ...
1
vote
1answer
38 views

Why Nitrides have internal polarization?

Why GaN has internal polarization? I know that in wurtzite crystal structure, the atomistic bonds are not equivalent and as a result there appears a net dipole and consequently a polarization. But ...
1
vote
1answer
154 views

Structure factor of crystals (X-ray crystallography)

How can one prove that the degree of each node in a distance graph must be at least four in order to obtain a unique solution to an exact distance geometry problem with sparse distance data? The ...
0
votes
1answer
236 views

How are lattice parameters determined from reciprocal space maps?

It seems that the papers speak of reciprocal space maps with very high praise because of its ability to study strain in epitaxial films and determine the amount of relaxation. Also one can determine ...
0
votes
1answer
34 views

Understanding Braggs x-ray diffraction and why light is treated as a single “ray/line”

I'm not familiar with optics. So my knowledge of treating light as single lines is almost completely foreign to me. Although I do know something about EM waves and Maxwells equations, so you can ...
0
votes
1answer
73 views

Why can the twin plane be uncoincide with the composition plane in reflection twin?

In the book Elements of X-Ray Diffraction, p67, I found the following sentence: In the case of a reflection twin, the composition plane may or may not coincide with the twin plane. But I think ...
0
votes
1answer
28 views

Is it more difficult to create higher energy photons, given there is excess available energy?

Im not talking about pair production, I mean a single photon created from an energy transition between two electron shells. I'm studying K(alpha) and K(beta) fluorescence transitions in metals, and ...
2
votes
0answers
190 views

Pseudocubic unit cells: how to construct one?

I keep coming across the term pseudocubic unit cell while reading about orthorhombic perovskite structures. No clear explanation ...
1
vote
0answers
29 views

Can the hole concentration of cuprate superconductors generally be determined from lattice parameters?

As it is known, in YBCO superconductors, lattice parameters are strongly dependent on hole concentration, so hole concentration can be determined by measuring the c-axis parameter, see e.g. "Oxygen ...
1
vote
0answers
27 views

Process of x-ray crystallography

This is a pretty basic question but I would just like some confirmation of what I suspect is true. As I understand it, the basic idea behind x-ray crystallography is that we take our crystal and hit ...
1
vote
0answers
61 views

Four dimensional Bravais lattice

I am wondering if there are any reference on four dimensional Bravais lattice and their primitive vectors, even an example will help.
1
vote
0answers
146 views

How to identify a crystal structure by its x-ray reflection bragg angles?

How to identify a crystal structure by its x-ray reflection bragg angles? Suppose we have a crystal sample to examine its crystal structure (e.g. SC, BCC, FCC, etc). What we can get from an X-ray ...
1
vote
0answers
761 views

The reciprocal lattice of HCP lattice

There is a very similar question here Reciprocal Lattice of a non-bravais lattice, but I don't fully understand the answer, and the question is now obsolete so I feel that I should ask it again. How ...
1
vote
0answers
171 views

How do I use MAUD for phase quantification of XRD data with AMCSD standards?

I'm a biologist with some raw powder XRD data of biominerals, need to quantify different phases, can't access commercial software or databases at the moment. Does anyone have experience with using ...
1
vote
0answers
72 views

Reciprocal space maps units

I have seen reciprocal space maps in different units. In some figures, it is represented in delta(l) delta(h) reciprocal space maps units. In some figures it is shown in Q(parallel) and Q(normal) ...
1
vote
0answers
85 views

Why does inelastic X-ray scattering probe the longitudinal dielectric function as opposed to the transverse dielectric function?

Light is a transverse wave. Therefore, light in the optical range (i.e. visible light) couples to transverse collective excitations of a material when measuring the optical conductivity for instance. ...
0
votes
0answers
7 views

Position in reciprocal lattice (for Triangular real lattice) to find photonic gapmap

To find Gap-Map, using FDTD, for square lattice of dielectric coulumns in air, I choose the 'X' position in reciprocal lattice, while varying the radius of the rods. The result is good. But while ...
0
votes
0answers
27 views

Sum rule in X-ray Photoelectron Spectroscopy (XPS)

What is the sum rule in X-ray Photoelectron Spectroscopy (XPS)? how can I derive it? Can anybody explain the principle of sum rule in XPS or in spectroscopy in general? How can I apply it to a ...
0
votes
0answers
25 views

About X-ray Dynamical Diffraction

I am studying X-ray Dynamical Diffraction. I understood that X-ray Dynamical theory is used when higher-order scattering or multiple scattering terms in the Born series become important and cannot be ...
0
votes
0answers
20 views

Iron-carbon bistable structure

I have just extracted the metallic inner part of a safety wristband (a bi-stable structure), and performed an EDX analysis. I found that it is composed of $Fe$ ($86$ wt%) and $C$ ($5.5$ wt%) and $O$ ...
0
votes
0answers
26 views

XRD and Superconducting Volume Phase

I have prepared H-Tc Superconductors polycrystalline samples. In the XRD pattern there is not extra peaks and we can say the sample is pure, without impurities. But SQUID shows that only 60% is ...
0
votes
0answers
25 views

How to determine film thickness in a multilayer sample

What is the mathematical derivation or formula to determine thickness of each film in a multilayer sample with the help of X-Ray Reflectivity technique?
0
votes
0answers
42 views

How to estimate the lattice parameter from a Debye-Scherrer diffractogram

The question is: In a Debye-Scherrer diffractogram, centers of maximum intensity were noted at the following angles with respect to the straight through position (all these angles are in degrees): ...
0
votes
0answers
22 views

Does the EXAFS oscillations occur when ultrashort x-ray pulse is used? Electron with a 50eV kinetic energy will travel in 0.1fs 4.2 Angstroms

In X-ray extended absorption spectroscopy (EXAF) an electron is excited by an x-ray photon into the continuum, the outgoing electron wave interferes with the scattered electron wave from the ...
0
votes
0answers
3k views

How to calculate lattice parameter of wurtzite struture

I am trying to calculate lattice parameter of ZnO (wurtzite). I have found out the formula for calculating lattice parameter of this system from a research article. $\frac{1}{^{d^{2}}}=\frac{H ^{2}+ ...