Condensed Matter Physics Important Questions

Bsc/Msc Physics 

Part 1

Unit 1: Crystal Structure 

1. Explain bravais lattice in two and three Dimension?
2. Explain the simple crystal Structure of Cscl, NaCl, ZnS, Diamond and Hexagonal closed packed structures?
3. Find out number of atoms in per unit cell and coordination number in simple crystal Structure?

Unit 2: Crystal Diffraction by X—Ray

1. What is reciprocal lattice of crystal?
2. Prove that the volume of unit cell of reciprocal lattice is inversely proportional to the volume of unit cell of direct lattice?
3. Find out the reciprocal lattice and translation vector for BCC/FCC/SCC lattice?
4. Derive the relation for translation vector between direct and reciprocal lattice?
5. What is brillouin zone explain it?
6. Explain Bragg Diffraction condition in terms of reciprocal lattice vector?
7. Explain the reciprocal lattice of bcc lattice?
8. Explain the reciprocal lattice of fcc lattice?
9. Give the relation between crystal lattice axes and crystal reciprocal lattice axes?
10. Find the primitive vectors for the reciprocal lattice of FCC/ BCC lattice?

Unit 3: Elastic Properties of Solids

1. Define stress and strain. Explain their components in a solid?
2. Explain elastic constants for isotropic body?
3. What are elastic compliance and stiffness constants? How are they related?
4. Derive the expression for elastic energy density in an isotropic solid?
5. Explain elastic energy density in terms of stiffness constant?
6. Discuss the reduction of the number of elastic constants in different symmetry conditions?
7. Explain the concept of elastic stiffness constants for an isotropic body?
8. What is the elastic constant for cubic isotropic bodies? How is it determined experimentally?
9. What is elastic wave? Find out elastic wave in (100) direction?
10. Derive the equation for elastic waves in solids and discuss wave propagation in the (100) direction?
11. Explain the final velocity of elastic waves of a cubic crystal in (100) direction?

Unit 4: Lattice Vibration and Phonons

1. Describe the lattice dynamics/ Vibration of a diatomic linear lattice?
2. Explain the optional and acoustic mode of vibration?
3. What is a lattice vibrational spectrum? How is it obtained?
4. Explain the concept of phonons. How do they contribute to the thermal properties of solids?
5. What is Phonon?  Explain the angular frequency of Phonon in solids?
6. Derive the expression for the momentum of a phonon?
7. Explain the inelastic scattering of photons by phonons. Give an example?
8. How does inelastic scattering of neutrons by phonons help in understanding lattice vibrations?
9. Discuss the inelastic scattering of X-rays and its significance in solid-state physics?

Unit 5: Thermal Properties and Band Theory of Solids

1. Explain the thermal conductivity of solids/crystals?
2. What is anharmonicity? How does it affect the thermal expansion of solids?
3. Derive the equation of state for a solid and explain its significance?
4. Define the Grüneisen constant and discuss its role in thermal expansion?
5. Explain the band theory of solids. How does it classify materials into conductors, semiconductors, and insulators?
6. What is the concept of effective mass in semiconductors? How is it determined?
7. Define Fermi surfaces and discuss their importance in electronic properties of solids?
8. What is the anomalous skin effect? How does it influence electrical conductivity?
9. Explain the De Haas-van Alphen effect and its applications in solid-state physics?
10. Describe the phenomenon of cyclotron resonance and its applications?
11. What is magnetoresistance? Discuss its significance in modern electronic devices?

Part 2

Unit 1: Superconductivity

1. What is a superconducting state? What are its key characteristics?
2. Explain the concept of persistent current in superconductors?
3. What is the critical temperature in superconductors? How is it determined?
4. Describe the Meissner effect? Why is it important for superconductivity?
5. Explain the thermodynamics of superconducting transitions?
6. Derive the London equation and explain penetration depth?
7. What are coherence length and its significance in superconductors?
8. Differentiate between Type I and Type II superconductors?
9. Explain the BCS theory of superconductivity?
10. What are AC and DC Josephson effects?
11. What is Josephson effect? Describe Josephson Tunneling and its applications?

Unit 2: Magnetism

1. What is Weiss theory of ferromagnetism?
2. Explain the Heisenberg model in the context of magnetism?
3. Describe the molecular field theory of ferromagnetism?
4. What are domain walls? How do they contribute to magnetic properties?
5. Explain Bloch wall energy and its significance?
6. What are spin waves and magnons?
7. State and explain Curie-Weiss law for magnetic susceptibility?
8. Differentiate between ferrimagnetism and antiferromagnetism?

Unit 3: Imperfections in Crystals

1. What are the different types of atomic packing imperfections?
2. Explain point defects in crystals with examples?
3. What are interstitial defects? How do Schottky and Frenkel defects differ?
4. Describe lattice vacancies and color centers in crystals?
5. What are F centers and F' centers? How are they formed?
6. Explain the coagulation and production of color centers and V centers?
7. What are line defects in crystals? Give examples?
8. Explain edge and screw dislocation in crystalline solids?
9. Describe the mechanism of plastic deformation in solids?
10. How do stress and strain fields affect dislocations in solids?
11. Explain the Burgers vector and its significance in crystal defects?
12. What is shear strength in single crystals? How does it influence material properties?

Unit 4: Thin Films

1. What are thin films? How are they different from bulk materials?
2. Explain the role of surface topography in thin film studies?
3. How does a multiple beam interferometer help in thin film analysis?
4. What are the conditions for accurately determining step height in thin films?
5. Explain the importance of Fizeau fringes in the measurements?
6. Explain how film thickness is measured using Fizeau fringes?
7. What are the factors affecting the electrical conductivity of thin films?
8. Derive an expression for electrical conductivity in thin films?
9. Derive the expression for the measurement of electrical conductivity of thin films? Determine the galvanomagnetic coefficient?
10. Explain the Hall effect and their applications?
11. What is the Hall coefficient? How does it apply to thin films?
12. Explain the quantum size effect in thin films?

Unit 5: Nanostructures

1. What are the quantum dots?
2. What are carbon nanotubes? Classify them?
3. What are nanostructures? How are they classified?
4. Discuss the properties of nanostructured materials?
5. What are nanoparticles? Explain their uses?
6. Explain the different methods of preparing nanomaterials?
7. How does plasma-enhanced chemical vapor deposition work?
8. What is electro-deposition, and how is it used in nanotechnology?
9. Describe the structure of single-wall carbon nanotubes?
10. Explain the classification of carbon nanotubes based on their properties?
11. What are chiral vectors in carbon nanotubes?
12. Define translational vector T and symmetry vector R in nanotube structures?
13. What is the concept of the Brillouin zone in nanomaterials?
14. Discuss the electronic properties of nanostructures?
15. Explain the mechanical behavior of nanomaterials?
16. How do thermal and phonon properties affect nanomaterials?