3.8 Conclusions
99
has been discussed. Furthermore, periodic superlattice structure has also been highlighted. Most currently available commercial spintronic products, such as magnetic
read heads for reading data in computer hard disks, magnetic random access memory
etc. are based on giant magnetoresistance effect.
3.9 Exercises
1. What is magnetoresistance? How does the external applied magnetic field
affect the resistivity in a metal?
2. What is ordinary or normal magnetoresistance?
3. Describe magnetoresistance of ferromagnetic transition metals.
4. What is anisotropic magnetoresistance (AMR) of ferromagnetic transition
metals?
5. Calculate the normal magnetoresistance in Cu and in Co at room temperature
for an applied field of 1 T? The resistivity of Co (Cu) is 10 (1) μcm and R H
(Cu) = −5 × 10
−10 C
−1 m
−3 and R H (Co) = 1 × 10
−9 C
−1 m
−3 [Ans: MR for
Cu and Co is of the order of 10
−3 and 10
−4 at room temperature, respectively].
6. How do we determine the magnetoresistance in multilayer films?
7. What are the different types of scattering that destroy the magnetoresistance
in multilayer films?
8. Are 3d transition metal good conductors as compared to copper?
9. What are the factors that determine the GMR in multilayer samples and how
to enhance the GMR in multilayer films?
10. Define magnetoresistance (MR).
11. What are spin-dependent and spin-flip scattering? What are different types of
scattering that destroy magnetoresistance in multilayer films?
12. What is GMR?
13. How is GMR effect?
14. Define different types of GMR.
15. Differentiate between multilayer GMR and spin valve GMR.
16. What is the difference between spin valve GMR and pseudo-spin valve GMR?
17. What is granular GMR?
18. What is spin-dependent and spin-flip scattering of electrons in multilayers?
19. How does Mott model describe GMR?
20. Explain negative magnetoresistance of ferromagnetic transition metal, considering spin scattering mechanisms.
21. What is periodic superlattice structure?
22. Derive the equation for determining GMR using resistor network theory.
23. Distinguish between spin-dependent scattering and spin-flip scattering of
electrons in multilayers.
24. Define GMR effect. Discuss the physical origin of GMR in a trilayer structure
using a simple resistor model.
99
has been discussed. Furthermore, periodic superlattice structure has also been highlighted. Most currently available commercial spintronic products, such as magnetic
read heads for reading data in computer hard disks, magnetic random access memory
etc. are based on giant magnetoresistance effect.
3.9 Exercises
1. What is magnetoresistance? How does the external applied magnetic field
affect the resistivity in a metal?
2. What is ordinary or normal magnetoresistance?
3. Describe magnetoresistance of ferromagnetic transition metals.
4. What is anisotropic magnetoresistance (AMR) of ferromagnetic transition
metals?
5. Calculate the normal magnetoresistance in Cu and in Co at room temperature
for an applied field of 1 T? The resistivity of Co (Cu) is 10 (1) μcm and R H
(Cu) = −5 × 10
−10 C
−1 m
−3 and R H (Co) = 1 × 10
−9 C
−1 m
−3 [Ans: MR for
Cu and Co is of the order of 10
−3 and 10
−4 at room temperature, respectively].
6. How do we determine the magnetoresistance in multilayer films?
7. What are the different types of scattering that destroy the magnetoresistance
in multilayer films?
8. Are 3d transition metal good conductors as compared to copper?
9. What are the factors that determine the GMR in multilayer samples and how
to enhance the GMR in multilayer films?
10. Define magnetoresistance (MR).
11. What are spin-dependent and spin-flip scattering? What are different types of
scattering that destroy magnetoresistance in multilayer films?
12. What is GMR?
13. How is GMR effect?
14. Define different types of GMR.
15. Differentiate between multilayer GMR and spin valve GMR.
16. What is the difference between spin valve GMR and pseudo-spin valve GMR?
17. What is granular GMR?
18. What is spin-dependent and spin-flip scattering of electrons in multilayers?
19. How does Mott model describe GMR?
20. Explain negative magnetoresistance of ferromagnetic transition metal, considering spin scattering mechanisms.
21. What is periodic superlattice structure?
22. Derive the equation for determining GMR using resistor network theory.
23. Distinguish between spin-dependent scattering and spin-flip scattering of
electrons in multilayers.
24. Define GMR effect. Discuss the physical origin of GMR in a trilayer structure
using a simple resistor model.