Mid Infrared Spectromicroscopy (Mid-IR)

Samples

Sample Types

The Mid-IR beamline is ideal for studying biomedical and biological materials, agricultural and environmental samples, materials such as polymers, art specimens, and much more!

This guide is designed as a starting point for sample preparation for experiments at Mid-IR. Please talk to beamline staff about your specific samples and unique requirements to ensure high quality data collection is possible.

Sample Preparation

The Canadian Light Source has several user accessible labs. Basic lab access requires the completion of CLS Laboratory Safety Training.

General lab equipment includes: Ultrasonic cleaners, ovens, balances, pH meters, pipettors, microscope, fume hoods, hot plate, freezers, refrigerators, and much more!

Specialized equipment are in the electrochemistry lab, SyLMAND, earth sciences lab and life sciences lab.

Our CLS Laboratories and Equipment page contains full details and locations of each lab.

Sample Holders

There are many standard sample holders available to use at Mid-IR

Pictured for transmission :

A) holder for two 25 mm CaF2 windows

B) Liquid cell, uses 25 mm CaF2 windows

C) Holder for one 25 mm CaF2 window

D) Holder for four 10 mm CaF2 windows

sample_holders.PNG

Windows

About windows

Calcium Fluoride (CaF2) are commonly used at Mid-IR as a sample support. The windows come in a variety of sizes and thicknesses. Sizes 25 mm and 10 mm (thickness 1 mm) are supported with the standard sample holders, other sizes can be accommodated, but arrangements must be made well in advance of beam time. Properties of mid-IR optic materials are listed in the table below.

Where to buy

User groups will supply their own IR windows. They can be purchased from Crystran.

How to clean

Windows of different materials will have different cleaning protocols.

CaF2 windows can be cleaned with water and are acid/base resistant. The windows can be dried and gently polished with lens paper

BaF2 windows are extremely sensitive to water and should not come into contact with water.

** Using clean windows is incredibly important for collecting high quality data **

Comparison of Common Infrared optic materials

material

transmission range (cm⁻¹)

index of refraction

advantages

disadvantages

CaF₂

66,000 - 1200

1.40

insoluble in water

more expensive than BaF₂

BaF₂

50,000 - 900

1.45

lower cut-off than CaF₂

sensitive to water

Ge

5000 - 600

4.01

high refractive index

 

ZnSe

20,000 - 500

2.43

low cut-off

soluble in strong acid

ZnS

22,000 - 750

2.25

insoluble in water

soluble in acid

Si

10,000 - 100

3.42

insoluble in most acids and bases

 

Storage

Samples mailed to the Mid-IR for mail-in or remote access experiments can be stored until beamtime. Some options include

  • Refrigerator (5 °C)

  • Freezer (-20 °C)

  • Extra cold freezer (-80 °C)

  • Desiccator

Need a storage location not listed? Please contact beamline staff to figure out a solution.


Sample disposal

Samples need to be removed when your beam time is finished. In the case of mail-in and remote access, samples will be returned to the user or disposed of if specific instructions are provided.