Nanotechnology: A Maker's Course Week 2

What is the critical electron-beam interaction that emits a characteristic x-ray from a sample in Energy Dispersive X-Ray Spectroscopy (EDS)?

(not Electrond bombarding the sample)

In SEM, what is the sample mounted on to prepare for imaging?

A sample stub

How might functions of the electron microscope be used in an Energy Dispersive X-Ray Spectroscopy (EDS) experiment?

All of the above

If you are interested in collecting SEM images that highlight differences in atomic species, which detector would be more appropriate?

Backscatter

In SEM, which of the following materials is often used to coat nonconductive samples?

Carbon

Which of the following information can be obtained through Energy Dispersive X-Ray Spectroscopy? (Select all that apply)

Chemical Composition Elemental Composition

Which of the following can achieve higher resolution?

Electron

What makes each element have a unique fingerprint in Energy Dispersive Spectroscopy (EDS)?

Electron energy states in the element

If an insulating sample is coated with a very small layer of gold to produce better images, gold will not be detected in the Energy Dispersive X-Ray Microscopy (EDS) experiment.

False

In Energy Dispersive Spectroscopy (EDS), it's impossible to misidentify elemental composition of a sample.

False

Images collected by the backscatter detector appear ________ (Select the best answer).

Flat

In SEM, after loading the sample and pumping the chamber to a low pressure, what should be done first before collecting an image?

Focus the electron beam on the sample

In SEM, which of the following materials is often used to coat nonconductive samples?

Gold

Which of the following uses light to generate images?

Light microscope

When using an SEM, stigmation is adjusted on the microscope to ensure that imaging is done with a(n) _______ beam of electrons.

Round

Which of the following statements are true? Select all that apply.

The contrast thar we see in a backscatter image is due to differences in average atomic number Secondary electron images look very 3 demensional Secondary electron images show the surface feature of a sample (Both secondary electron and backscattered SEM images provide useful information about a sample. Secondary electron images show the surface features of a sample, and therefore look very 3 dimensional. Backscatter SEM images show fewer surface features than secondary electron images. Often backscatter images look very flat. The contrast that we do see in a backscatter image is due to differences in average atomic number. Regions of the sample with higher atomic number will produce more backscattered electrons and appear bright.)

Images collected by the secondary electron detector appear ________ (Select the best answer).

Three-dimensional

After Energy Dispersive X-Ray Spectroscopy (EDS) is performed on a sample, it can be reused in further tests.

True

Which of the following may be components used in an Energy Dispersive X-Ray Spectroscopy (EDS) measurement? (Select all that apply)

X-Ray Sofrware Electron Microscope Electron Gun

In backscattered SEM images, regions of the sample with higher atomic number appear bright because atoms in this region _________.

produce more backscattered electrons

What is an advantage of using an environmental scanning electron microscope?

water in the sample can be used to prevent charging, elimianting the need for conductive coating.