What is secondary ion mass spectrometer used for?
Secondary ion mass spectrometry (SIMS) is a technique used to analyze compositions of thin films and surfaces by using a focused primary ion beam to sputter the surface of a sample and analyze the ejected secondary ions.
What can SIMS detect?
Secondary Ion Mass Spectrometry (SIMS) detects very low concentrations of dopants and impurities. The technique provides elemental depth profiles over a wide depth range from a few angstroms (Å) to tens of micrometers (µm).
What is secondary ion emission?
Secondary ion emission by a solid surface under ion bombardment supplies information about the elemental, isotopic and molecular composition of its uppermost atomic layers. The secondary ion yields will vary greatly according to the chemical environment and the sputtering conditions (ion, energy, angle).
Is secondary ion mass spectrometry destructive?
Secondary ion mass spectroscopy (SIMS) is a destructive analytical technique in which material is removed from a surface by ion beam sputtering, and the resultant positive and negative ions are mass analyzed in a mass spectrometer [62].
What is ToF SIMS analysis?
Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a surface-sensitive analytical method that uses a pulsed ion beam (Cs or microfocused Ga) to remove molecules from the very outermost surface of the sample. The particles are removed from atomic monolayers on the surface (secondary ions).
Can SIMS detect oxides?
Oxygen isotope exchange with subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a highly valuable tool for determining oxygen diffusion coefficients in oxides.
Can SIMS detect hydrogen?
SIMS can readily detect hydrogen and the isotopes deuterium and tritium.
How does ion mobility spectrometry work?
In an ion mobility spectrometer, organic molecules are ionized and driven by an electric field against a counterflow of neutral drift gas. In their way to the detector, the ions collide multiple times with the drift gas, which reduce their speed. After each collision, ions are accelerated again by the imposed field.
Can SIMS detect different isotopes?
“Conventional” SIMS instruments mostly use large radius magnetic sectors nowadays. They have a lateral resolution of a few µm and can detect simultaneously up to five isotopes in a small mass range. They are usually used for high precision spot analyses of isotopes with a precision reaching 0.1‰.
How do you read TOF data on Sims?
TOF-SIMS spectra are typically displayed as a plot of signal intensity or ion counts on the Y-axis versus m/z on the X-axis. The height of a signal is proportional to the amount of that ion present in the spectrum and the m/z of the ion is basically the mass of that ion (if it is singly charged).
Is TOF-SIMS quantitative analysis?
We demonstrate the effects of protein orientation and trehalose on a quantitative analysis of surface-immobilized proteins by using time-of-flight secondary ion mass spectrometry (TOF-SIMS).
Can Sims detect different isotopes?
Why to ionise in mass spectrometry?
Why is it necessary to ionise molecules when measuring their mass in a TOF mass spectrometer? Ions will interact with and be accelerated by an electric field Only ions will create a current when hitting the detector
What are some disadvantages of mass spectrometry?
This gives the relative molecular mass of every molecule. The main disadvantage of mass spectrometry is that it is costly, need a skilled technician, and it is not a portable system. We will unable to differentiate among isomers of the molecule with the same charge-to-mass ratio. Chiral columns may be required to separate enantiomers.
What is secondary ion mass spectroscopy?
Secondary-ion mass spectrometry (SIMS) is a technique used to analyze the composition of solid surfaces and thin films by sputtering the surface of the specimen with a focused primary ion beam and collecting and analyzing ejected secondary ions.
What is mass spectrometry and how does it work?
– Give a good estimate of the purity of the sample (i.e. whether there are one or more molecular species in your sample and what ratio those species are in) – Monitor reactions, sequence amino acids, and oligonucleotides as well as give information on protein structure – Identify and quantify samples