Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
93 views
in General by (103k points)
closed by

In which of the following techniques, beam of electrons is used as a probe, and the secondary radiation is X-ray.

(A) LEED

(B) EMP

(C) TEM

(D) STEM

(E) EELS

Choose the correct answer from the options given below


1. (A) and (E) only
2. (B) and (D) only
3. (C) and (E) only
4. (A) and (C) only

1 Answer

0 votes
by (106k points)
selected by
 
Best answer
Correct Answer - Option 2 : (B) and (D) only

LEED: LEED is the principal technique for the determination of surface structures. It may be used in one of two ways:

Qualitatively: Here, the diffraction pattern is recorded and analysis of the spot positions yields information on the size, symmetry, and rotational alignment of the adsorbate unit cell with respect to the substrate unit cell.
Quantitatively: Here, the intensities of the various diffracted beams are recorded as a function of the incident electron beam energy to generate so-called I-V curves which, by comparison with theoretical curves, may provide accurate information on atomic positions.

EMP: Electron probe microanalysis (EPMA) (also known as wavelength-dispersive electron microprobe analysis) is used in the analysis of artifact composition; this technique is similar to X-ray fluorescence and is useful for studying small changes in composition within the body of an artifact as the penetration depth is up to 5 μm.

TEM:

  • TEM is another microscopy technique in which a beam of electrons is transmitted through an ultrathin sample, and interacts with the specimen as it passes through it.
  • The resolution of TEM is higher than that of SEM.
  • The sample prepared for TEM is thin so that electrons can pass through.

STEM:

  • Scanning transmission electron microscopy (STEM) combines the principles of transmission electron microscopy and scanning electron microscopy and can be performed on either type of instrument.
  • Like TEM, STEM requires very thin samples and looks primarily at beam electrons transmitted by the sample.
  • One of its principal advantages over TEM is in enabling the use of other signals that cannot be spatially correlated in TEM, including secondary electrons, scattered beam electrons, characteristic X-rays, and electron energy loss.

EELS:

  • Electron energy loss spectroscopy (EELS) is a family of techniques that measure the change in kinetic energy of electrons after they interact with a specimen.
  • This technique is used to determine the atomic structure and chemical properties of a specimen, including the type and quantity of atoms present, the chemical state of atoms, and the collective interactions of atoms with their neighbors.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...