An Electron Probe Micro- Analyzer is a micro-beam instrument used Primarily for the non-destructive chemical Analysis of minute Solid Sample.
Basic Principle :
EPMA works by bombarding a micro-volume of a Sample with a focused electron beam (typical energy=5-30 KeV) and collecting the X-ray photons thereby emitted by the various elemental species. Because the wavelengths of these X-rays are characteristic of the emitting species, the sample composition can be easily identified by recording WDS Spectra (Wavelength Dispersive Spectroscopy). WDS Spectrometers are based on the Bragg’s Law and use various moveable, shaped Monocrystals as Monochromators.
● WDS used in an EPMA is characterised by a higher level of energy resolution than EDS and EPMA is capable of analysis with higher accuracy and sensitivity being a surface characterization technique.
● Better S/N ratio than EDS.
● EDS Energy Resolution – Lower ~ 125eV
● WDS Energy Resolution – Higher ~ 5-10eV
● More efficient technique for the concentration of specific known Elements.
Instrument Model : EPMA -1720 HT
Make of EPMA : SHIMADZU , Japan
Both Standard and Standard less analyses are possible in EPMA with ZAF correction for different sets of alloys and Compounds.
Both Standard and Standard less analyses are possible in EPMA with ZAF correction for different sets of alloys and Compounds.
1. QUALITATIVE ANALYSES :
To determine the type of elements that comprise the analysis sample.
2.
WDS AREA MAPPING ANALYSES:
To Determine the concentration distribution of elements on the surface by generating a two dimensional map with better resolution than EDS.
.3. QUANTITATIVE ANALYSES :
To Determine the concentration (quantitative value) of each element in a known sample by measuring X-ray signal intensity of standard samples and then the known sample with much precision & accuracy as compared to EDS.
4. Qualitative Line Analysis:
To Determine the Elemental distribution along a straight line on the sample in the form of a line Profile.
5. Image Observation :
Secondary Imaging, Backscattered Imaging.
6. QUANTITATIVE EPMA : Two “Zeroth” order conditions must be fulfilled
(a). The Specimen must have no factors other than Composition differences affecting the measured X-ray intensities. Geometric Factors(surface irregularities) must be eliminated by careful Polishing (No Etching).
(b). The Specimen must be Homogeneous over the interaction volume (dimensions~1um) that the beam excites.
a) The surface for observation or analysis should be fresh and have representative properties of the observation or analysis objective.
● Sample acquisition methods, securing and storage methods.
b) Must withstand Observation or analysis in a vacuum environment.
● Drying methods, Freezing Methods and elimination of volatile ingredients.
c) Should be Conductive. If the material itself is not conductive, the sample layer at the point of irradiation or its vicinity must be conductive.
● Coating Methods
d) Should have thermal Conductivity or Heat resistance.
e) Should be as smooth, flat and level as possible (especially Quantitative Analysis)
● Mirror Polish, Flat, Non-Porous, Vacuum Dessicated, Solid without Moisture, Non - Magnetic(Non-Ferromagnetic), No loose particles on Observation Surface. A Palette has to be made for Powder Sample Analysis.
f) Any Solid structure like in SEM within a Maximum range of sample size of approx 20mm dia and 10mm height is acceptable. Bring Fresh CD for EPMA which should not be used for other equipment’s data.
1. Registration process (One Time): New Registration for external users.User Verification: Upload photo of Front side and back side of valid Identity card issued by the organization (only .jpeg format, file Size less than 1 Mb, height less than 1000 pixels, width less than 800 pixels). Undertaking: Download the undertaking template ( Download Link ). Duly filled, signed and stamped form should be uploaded in .pdf format. Confirmation: An email will be sent to the user after verification of the documents.
2.Before planning to avail the Instrument facility of CRF IIT Delhi: user must visit https://crf.iitd.ac.in -> Facility -> select the desired facility from left side navigation list. Read carefully all the relevant information such as required sample type, testing charges and instrument location. Be prepared with details of the samples.
3.Log in and Click on Booking Appointment Tab: All the information relevant to testing must be filled in instrument booking form. In case user does not provide the required information the booking is liable to be rejected. User can upload the relevant existing data of their samples that might help in the measurements.
4.Sample submission & Payment Process: Once the application is submitted, the in-charge will verify the details and approve the request.External users must wait for the approval before making the payment and submitting the samples to concerned lab. After approval the payment should be made by the user. The payment transaction details need to be submitted online before appointment date time.
5.CRF Users can pay amount online using following details:
Beneficiary/Customer's Name: IRD ACCOUNT IITD
Bank Account Number: 10773572600
Bank Name: State Bank of India Branch Name: IIT Branch
Branch Code: 01077
NEFT IFSC CODE / RTGS: SBIN0001077
please write "CRF _Instrument Name" in the Remarks section while paying. Save the receipt file and upload in the crfbooking system online against your application.Payment can also made in form of demand draft in favour of " IRD ACCOUNT IITD " Payable at New Delhi.6.IIT Delhi
GST Number : 07AAATI0393L1ZI
PAN Number : AAATI0393L
1 Registration process (One Time): New Registration for internal users.
Fill in all the details in Personal Information, Supervisor Information and User Login Credentionals.
Once submitted, an email to supervisor is sent for activation of account. Once activated by supervisor, you can do the instrument bookings.
2 Before planning to avail the Instrument facility of CRF IIT Delhi: user must visit https://crf.iitd.ac.in > Facilities > select the desired facility from left side navigation list. Read ca 
refully all the relevant information such as required sample type, testing charges and instrument location. Be prepared with details of the samples.
3. Log in on CRF Booking System and Click on Booking Appointment Tab: All the information relevant to testing must be filled in instrument booking form. In case user does not provide the required information the booking is liable to be rejected. User can upload the relevant existing data of their samples that might help in the measurements.
4 Sample submission & Payment Process: Once the application is submitted, the in-charge will verify the details and approve the request.
