## What is instrument broadening?

Instrumental broadening has to be subtracted* to obtain broadening from other sources. This is done by using a ‘standard’ sample with large grain size and low strain, wherein there is no crystallite size or strain broadening (sample is chosen such that the density of other defects is small).

**What are reasons for line broadening in XRD?**

Generally, any lattice imperfection will cause additional diffraction-line broadening. Therefore, dislocations, vacancies, interstitials, substitutions, and similar defects manifest themselves through the lattice strain.

### What is the relation between crystallite size and strain?

Effect of crystallite size on lattice strain and crystal structure has been studied using Rietveld refinement and Williamson-Hall plot, respectively. The structural lattice parameters decrease with increasing crystallite size. However, lattice strain increases with increasing crystallite-size.

**What is Williamson-Hall equation?**

In the “Williamson-Hall” following equation is used: βCosθ= Kλ/D+C.e.Sinθ Where β is the full width of the Bragg peak at half maximum (FWHM), θ is peak angle, D is mean crystallite size, e is strain and K~1. by comparing this to the standard equation for a straight line (m = slope; c = intercept)

## How do you find the lattice strain?

The ratio difference between lattice constants obtained from fitting and original value to original value gives the strain in material. i.e. strain = (a0 – a)/a where a0 gives lattice constant obtained from fitting and a – is original lattice constant.

**How the effect of instrumental broadening is eliminated?**

X-Ray, Synchrotron Radiation, and Neutron Diffraction The high intensity, collimation, and narrow energy band of a monochromatic SR beam have virtually eliminated the instrumental broadening of powder reflections.

### What does crystallite size tell us?

Crystallite size is the smallest – most likely single crystal in powder form. The crystallite size commonly determined by XRD. Grain is either a single crystalline or polycrystalline material, and is present either in bulk or thin film form. Therefore, particle is under no circumstances smaller than crystallite size.

**What determines crystallite size?**

diffraction profile

The crystallite size can be calculated from the full width at half maximum intensity (FWHM) measured on the corrected diffraction profile.

## What is meant by lattice strain?

Lattice strain is a measure of the distribution of lattice constants, such as lattice dislocations, which arise from crystal imperfections [4]. In order to minimize this strain, the rheo cast samples are subjected to T6 heat treatment.