Mössbauer Spectroscopy

1. Preparation of the Sample

1. Weigh 100 mg of ferrocene in a delrine Mössbauer cup.
2. Add several drops of paratone oil to the sample. Using a spatula, mix the sample and the oil into a uniform paste.
3. Freeze the sample in liquid nitrogen.

2. Mounting the Sample

1. Fill the sample chamber with He gas.
2. Unscrew the sample rod from the instrument and remove the sample rod.
3. While mounting the sample, close the sample chamber with a cap and secure with screws.
4. Load the Mössbauer cup into the sample holder at the end of the rod.
5. Tighten the screw to secure the cup in the sample holder.
6. Dust off any ice that forms before freezing the end of the sample rod in liquid nitrogen.
7. With He flowing through the sample chamber, unscrew and remove the cap, and insert the sample rod.
8. Secure the rod to the instrument with the screws.
9. Turn off the He and pull the vacuum on the sample chamber.
10. Turn off the vacuum and refill the sample chamber slightly with He to enable thermal exchange between the sample and the cold head of the instrument via the He gas.

3. Data Collection and Workup

1. Open the Mössbauer data collection software. Here we use W302 by Science Engineering & Education (SEE) Co.
2. The first screen will show the total count of gamma rays hitting the detector at a range of energies. Select the peak that includes the energy value 14.4 keV and 2 keV escape peak.
3. Hit the "Send Windows" button. This will send the data to the W302 software (SEE Co).
4. Open the W302 program. Select the desired source velocity (0-12 mm/s). Hit the "clear channel" to begin a new data collection.
   1. After the desired resolution is reached, fit the data with a suitable program. Here we use WMOSS by SEE Co. The fit provides the values for isomer shift and quadrupole splitting (if a doublet is present).