Week 6: X-Ray Fluorescence, X-Ray Diffraction & X-Ray Absorption Flashcards
What does XRF stand for?
X-Ray Fluorescence
True or False: XRF is used primarily for qualitative analysis.
False
What is the main principle behind XRF?
It measures the characteristic fluorescent X-rays emitted from a material when it is excited by a primary X-ray source.
Fill in the blank: XRF is commonly used in ________ analysis.
elemental
What does XRD stand for?
X-Ray Diffraction
What type of information does XRD provide?
It provides information about the crystal structure, phase identification, and other structural properties of materials.
True or False: XRD can be used to analyze both crystalline and amorphous materials.
False
What type of radiation is used in XRD?
X-rays
What is the main purpose of X-Ray Absorption Spectroscopy (XAS)?
To study the electronic structure and local environment of specific elements in a sample.
Fill in the blank: XAS is sensitive to the ________ of elements in a sample.
oxidation state
What does the term ‘absorption edge’ refer to in XAS?
The energy at which a specific element’s core electrons can be excited to unoccupied states.
Multiple choice: Which technique can provide information about the coordination environment of an element? A) XRF B) XRD C) XAS
C) XAS
True or False: XRF can detect elements down to parts per million (ppm) levels.
True
What is a common application of XRF?
Environmental monitoring and analysis of metals in soil and water.
What is the primary detector used in XRD?
A scintillation counter or a CCD detector.
Fill in the blank: In XRD, the ________ angle is critical for determining the crystal structure.
Bragg
What is one advantage of using XRF over other analytical techniques?
It is non-destructive and requires minimal sample preparation.
Multiple choice: Which technique is best suited for determining the mineral composition of a sample? A) XRF B) XRD C) Both A and B
C) Both A and B
What does the term ‘phase identification’ mean in the context of XRD?
Determining the specific crystalline phases present in a material based on its diffraction pattern.
True or False: X-Ray Absorption Spectroscopy requires a vacuum environment.
True
What is an application of XRD?
Analyzing the crystallinity of polymers.
What type of samples can XRF analyze?
Solid, liquid, and powder samples.
Fill in the blank: In XRF, the primary source of X-rays is typically an ________ tube.
X-ray
What is the role of the monochromator in XAS?
To select specific wavelengths of X-rays to probe the sample.
Multiple choice: Which technique provides quantitative elemental analysis? A) XRF B) XRD C) XAS
A) XRF
What is the significance of the ‘EXAFS’ region in XAS?
It provides information about the local structure around the absorbing atom.
True or False: The resolution of XRD is influenced by the size of the crystallites in the sample.
True
What is one limitation of XRF?
It cannot detect light elements effectively, such as lithium or beryllium.
Fill in the blank: XRD uses the ________ principle to analyze crystalline materials.
Bragg’s
What is the typical range of elements that XRF can detect?
From sodium (Na) to uranium (U).
Multiple choice: In which situation would XAS be particularly useful? A) To determine the composition of a solid sample B) To investigate the local environment of a specific element C) To measure the weight of a sample
B) To investigate the local environment of a specific element
