SIMS Technique

Secondary Ion Mass Spectrometry (SIMS) is used for the

chemical analysis of small volumes of solid material. In

SIMS the surface of the sample is bombarded under

vacuum with a finely focussed (typically ~1-25µm) beam

of primary ions (Cs+, O

+, O

-2 or Ar

+). The collision cascade

results in the ejection and ionisation of atoms and

molecules from the surface layers of the sample. These

secondary ions are accelerated into a double focussing

mass spectrometer where they are separated according

to their energy and mass/charge ratio before being

detected by electron multipliers or Faraday cups.

SIMS Instrumentation

Cameca ims-1270

1270 Specification

� Mass resolution up to 40,000.

� NMR or Hall probe control of the Magnetic field.

� Duoplasmatron ion source for either positive or

negative O ion generation.

� Cs microbeam ion source for the production of Cs+

ions.

� Oxygen flooding attachment for enhanced yield.

� Multi collector option installed with 3 electron

multipliers and 4 Faraday cups.

� Normal incidence electron gun for charge

neutralisation while analysing insulating specimens.

� Scanning ion image option for image collection.

Cameca ims-4f

4f Specification

� Mass resolution up to 10,000.

� Duoplasmatron ion source for either positive or

negative O or Ar+ ion generation.

� Robust, simple and intuitive software.

� Rapid magnetic peak switching from H to U.

� Scanning ion image option for image collection.

� An eight sample air lock system working at a

vacuum of <1*10-8

Torr.

� Residual gas analyser installed on the sample

chamber.

SIMS Strengths � Excellent detection sensitivity (down to ng/g).

� Depth profiles with excellent (nm) depth resolution.

� High spatial resolution (<1-25µm).

� Small analysed volume (down to 0.3µm3).

� Detection of virtually all elements and isotopes.

� Excellent dynamic range (over 6 orders of

magnitude).

� Routine quantitative analysis.

SIMS Limitations � Destructive technique.

� No chemical bonding information.

� Element specific sensitivity.

� Calibration is matrix dependent.

� Samples must be vacuum compatible.

� Samples must have a flat surface.

SIMS Detection Limits

H

Li

Na

K

Rb

Cs

Fr

Be

Mg

Ca

Sr

Ba

Sc

Y

La

Ac

Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge

B C N O F

He

Ne

Ar

Kr

Xe

Rn

Uuo

At

I

Br

ClS

Se

Te

Po

Uuh

Bi

Sb

As

PSiAl

Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn

Hf Ta W Re Os Ir Pt Au Hg Tl Pb

Rf Dd Sg HsBh Mt Ds Rg Uub

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Uuq

ng/g Detection Limit: Positive Secondary Ions

ng/g Detection Limit: Negative Secondary Ions

µg/g Detection Limit: Positive Secondary Ions

mg/g Detection Limit: Positive Secondary Ions

Not Detectable

Ra

SIMS Applications

More information go to: http://www.geos.ed.ac.uk/facilities/ionprobe/f-demo.htm

� Sr/Ca - SST Equations in Relation to Skeletal

Architecture in a Porites Coral.

� Zircon REEs as a probe of the oxidising environment

of magmas.

� Volatile contents of historical eruptions at Mt.

Ruapehu, New Zealand.

� Using δ18

O to assess the migratory route of Scottish

two sea-winter wild Atlantic salmon.

� U-Pb analysis of zircons: the Lochnagar Granite, NE

Scotland.

� Carbon Isotope Mapping and Diffusion in Diamond.

SIMS analysis pit for δ11

B

and REE, showing a melt

inclusion trapped in

Zircon. Analysis time 50

min using Cs+ and O

-

beam at ~5nA. (Analysis

and image by R.E. Jones).

SIMS analysis pit for

trace elements in Porites

coral. Analysis time

110min, 6nA O- beam.

(Analysis and image by N.

Allison)

SIMS Analysis Types

Trace Element Analysis

SIMS analysis allows the

detection of virtually all the

elements in the periodic table

often with ng/g (ppm) levels of

detection. Although the

technique is destructive, the

volume analysed can be <0.3µm3

Isotopic Analysis

The isotopic ratios may be

accurately determined if the

concentration and ionisation

efficiency allows. Typically ratios

of B, Li, C, O, Si, S can readily be

determined to <0.05%.

Geochronology

Age dating from Ma to 4.5Ga

using U/Th/Pb decay series in

Zircon, Apatite, Rutile and

Titanite can be achieved with a

precision of ~1% and a spatial

resolution of 15-25µm

Depth Profiles

As the ion beam slowly erodes

the atomic layers of the sample,

changes in the isotopic ratios are

recorded with nanometre depth

resolution.

Imaging

Images may be acquired by a

direct scanning ion image,

multiple spot analysis or depth

profiling. For many applications

the best technique is multiple

spot analyses.

Access Access is through the completion of the Ion Microprobe

Application Form that can be found on the Facilities web

page. For small projects (~2 weeks/yr) and pilot studies the

PI does not need a NERC research grant to be able to access

the Facility. Researchers eligible to apply for a NERC grant as

a PI or Co-I are also eligible to apply for access to the Facility.

For larger amounts of time a Research Grant Proposal must

be submitted to NERC and the time fully costed into the

application.

In both cases the required ion microprobe work must be

discussed in advance with the Facility Staff.

All proposals will be assessed by the Ion Microprobe Facility

Steering Committee that meets twice a year (May and

November). A successful project will be allocated Facility

time arranged between the Facility Staff and the applicant.

The Facility is also available for commercial work: Please

contact the Facility staff for a quotation.

Website:

http://www.geos.ed.ac.uk/facilities/ionprobe

Contact:

For further information please contact:

Dr. John Craven

(John.Craven@ed.ac.uk: 0131 650 4850 or 7887)

Dr. Richard Hinton

(Richard.Hinton@ed.ac.uk: 0131 650 4850 or 8548)

Dr. Jan C. de Hoog

(CdeHoog@ed.ac.uk: 0131 650 4850 or 8525)

Location:

Grant Institute,

School of Geosciences,

University of Edinburgh

West Mains Road,

EDINBURGH

EH9 3JW

NERC Ion Microprobe Facility (Edinburgh)

Secondary Ion Mass Spectrometry (SIMS)

http://www.geos.ed.ac.uk/facilities/ionprobe