DXR3xi ThermoFisher Scientific Raman Spectroscopy - SOP
This is the standard operational procedure (SOP) for the DXR3xi ThermoFisher Scientific Raman Spectroscopy.
Last updated
This is the standard operational procedure (SOP) for the DXR3xi ThermoFisher Scientific Raman Spectroscopy.
Last updated
Due to the inactivation of Skedda, Raman booking appointments are now done exclusively via this website: https://management.apcresearch.org/resources/lab/raman. NCI members are expected to adhere to the rules to ensure proper work ethics and safety procedures. Violation of safety rules may result in being reported to the respective user manager and suspended user access to Raman Spectroscopy. Any inquiries can be made by visiting the APC office at room 1B or via email at scheduling-raman@apcresearch.org.
PDF version is printable at the following link.
Users should understand the working principle and able to perform sample measurement using Raman Spectroscopy according to the instrument’s intended use.
To turn on the Raman spectrometer press the button on the machine (Figure 1). The sample is placed on the stage inside the sample compartment (Figure 2), and to move the stage in X, Y, and Z directions, use the microscope stage controls (Figure 3).
Before starting any measurements, please book the Raman machine beforehand through Skedda Website by first registering your email to the Skedda system. Link: https://management.apcresearch.org/resources/lab/raman
Before turning on the instrument, please make sure that the AC inside the room is turned on. Check the temperature and relative humidity of the room and make sure the temperature of the room is below the upper limit temperature of 27°C and stays that way throughout the analysis process. (If the temperature of the room reaches 28°C, stop all measurements and remove your sample from the sample compartment and wait until the temperature of the room to stabilize to begin your analysis).
Write down the sample details in the logbook, and ensure the water level in the water container of the humidifier is not overloaded or exceeding the marked limit. If the water level exceeds or approaching the marked limit, then please empty the water container before performing an experiment.
Before beginning any spectra acquisition, please first measure the SiO2 and HOPG standard reference.
Turn on the power source for the stage motor by pressing the green button, the cable light will turn blue if the power source for the motor has been turned on successfully (see Figure 4). Wait for 30 minutes.
Power up the instrument, hold down the power button for 3 seconds and make sure the power indicator turned blue. Wait for 30 minutes.
Turn on the computer.
Turn on the laser by turning the laser key on the left side of the instrument to an upright position (Figure 5) and make sure that the laser power indicator is on. Wait for 30 minutes.
Turn on the illuminator (Figure 6).
Make sure that there are no samples inside the compartment prior to booting up the software to avoid an error during the stage calibration.
Open the OMNICxi application and wait until the boot up process is finished.
Wait for 10-15 minutes for the laser to warm up.
The instrument is ready to use.
During the experiment you will spend most of your time in the acquisition screen.
For this example, a carbon-based material such as Highly Ordered Pyrolytic Graphite (HOPG) or a silicon wafer can be used as a calibrated standard.
To begin spectra analysis, prepare the sample by introducing the sample to an appropriate supporting substrate (silicon wafer or microscope slide) with a double tape or carbon tape to avoid from spilling the sample all over the stage, ideally such substrate should have contrasting color as the basic criterion when probed by Raman instrument.
Place your sample inside the stage and make sure that the sample is directly under objective lens using the stage controller (X and Y axis of the stage, see Figure 3). First use the 10x magnification.
When the sample is directly under the objective lenses, adjust the focus by turning on the knob on the right side of the controller (Z-axis control of the stage, see Figure 3) whilst paying close attention to the video panel. To speed up the process hold down rectangle button near the knob, if you observe that sample is in close proximity to the objective lens, then gently turn the knob to avoid bumping the sample into the objective lens until reaching the appropriate focus.
After adjusting the focus on the video panel, choose a region of interest (ROI) of sample surface for the spectral analysis using the stage controller.
After choosing an appropriate surface, choose the desired parameters to set up for your sample. Avoid using the laser at high power from the start to avoid burning your sample. For example, start the parameter at 1 mW laser power, 325 Hz exposure time and 10 number of scans. If the spectrum displays a lot of noise, gradually increase the parameter, starting from the number of scans to increase the signal to noise ratio and then the laser power and exposure time.
After setting up the desired parameter, click on the “live spectrum” tab, wait until the live spectra panel shows a live spectrum of the sample.
You can change the parameter if the signal-to-noise ratio is still low by increasing the number of scans and increasing or decreasing the laser power and exposure time, if needed, just be careful not to burn your sample.
To save your spectra click the “save spectrum” button and save the .spa spectrum in the appropriate folder path. (Alternatively, you can right-click on the spectra when you’re on the video mode and click “export” into .txt file).
The HOPG sample should have two distinctive Raman bands at around 1580 and 2721 cm-1, corresponding to G and D band. Whereas, a single peak centered at 519 cm-1 is observed for a SiO2 wafer.
Take out the sample by first clicking the “Video” tab, after that open the sample compartment and lower the stage using the Z-axis controller. After the sample is far enough from the objective lenses, gently move the stage away using the X, Y axis controller and then take out the sample.
For this example we will be using BA2CoCl4 2D perovskite sample as an example.
To obtain a Raman image, first load the sample in the stage just like before.
Make sure the sample compartment doors are tightly closed.
Move the BA2CoCl4 2D perovskite sample to the objective lenses to get the appropriate focus.
Obtain the spectra of the sample to be used for imaging (following the same steps in section C or by clicking select stored spectrum and select previously measured sample). Use minimum number of scans (no more than 10) to save imaging time and computer memory!
After obtaining a clear spectrum, click “zoom to region” button to center and scale the optical image to the mosaic pane.
Click “START Mosaic” to collect a mosaic. The mosaic is used to get a representative full view of the sample.
Use the preview box in the mosaic pane to select a region of interest and to obtain the preview chemical image. Center a small region of interest (ROI) in the preview box. If possible, select a region that is representative of all the regions you plan to analyze.
click “Apply Displayed Spectrum” above the “Select stored spectrum button”.
Select “Image Regions” mode located besides the “Live Spectrum” mode.
Click “Collect Preview”.
Adjust the image pixel size and Aperture settings, if needed, to optimize the image data if you think the current image data is not sufficient. Keep in mind that the image pixel size and the size of the aperture can affect the imaging time and memory consumption.
Make several regions for Raman mapping by clicking “Select Acquisitions Regions Manually” and make several region boxes for imaging.
When you are ready to collect the image data, click “Collect Regions” located at the top of the mosaic pane.
To save the acquired data, right click on the image in the analysis screen and click “Save Current Data”.
Save the imaging results in this directory path C:\users\public\Documents\Thermo\Omnicxi\Spectra. Name your file properly (Do not use spaces in your file name!) and save it. After confirming that the file has been successfully saved, Please immediately move your file to your folder in Local Disk D, to save computer memory.
Take out your sample after you are finished obtaining the raman imaging.
To begin a new imaging analysis, click “New Sample” on the top left corner and repeat the steps.
To turn off the instrument, close the OMNICxi application.
Turn off the computer and make sure it is completely turned off before powering down the instrument.
Turn off the illuminator (OLYMPUS TH4-200)
Turn the key to a horizontal position to turn off the laser.
Press the power button on the instrument for 3 seconds.
Turn off the stage motor power source.
This section lists the common issue or monitor warning and its solution. Should you encounter new problems, please notify the manager and email them to scheduling-raman@apcresearch.org.
This section lists the common issue or monitor warning and its solution. Should you encounter new problems, please notify the manager and email them to scheduling-raman@apcresearch.org.
For further information not covered in this SOP guidelines, please refer to the following guide:
select stored spectrum button
