Room temperature positive magnetoresistance

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SUMMARY

The discussion centers on the achievement of positive magnetoresistance (MR) in carbon nanotube (CNT) composite thin films with the inclusion of iron (Fe). The presence of Fe injects spin-polarized electrons into the CNTs, leading to an increase in resistance with the application of a magnetic field, which contradicts the expected decrease in resistance due to the spin injection. Experiments conducted in a magnetic field range of 0 to 1.1 tesla indicate that positive MR is contingent on the presence of Fe, as no MR was observed in pure CNTs. The factors influencing this phenomenon, including potential magnetostriction effects, are under investigation.

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  • Understanding of magnetoresistance principles
  • Knowledge of carbon nanotube (CNT) properties
  • Familiarity with spin-polarized electron injection
  • Basic concepts of magnetostriction in materials
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Researchers in materials science, physicists studying magnetoresistance, and engineers working with carbon nanotube composites will benefit from this discussion.

rejinisaac1
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I've achieved positive magnetoresistance (MR) in CNT composite thin films with a small percentage of Fe in it. Fe injects spin polarized electrons into CNT. But +ve MR means that resistance is increasing with magnetic field. But due to injection of spin polarized electrons the current has to increase and hence the resistance has to go down. Is my view right? If yes, what could be the factor that is leading to the increase in resistance? experiments were done in a range of 0 to 1.1 tesla. Please help me
 
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Could magnetostriction of the Fe in your CNTs be affecting the resistivity?
 
magnetostriction in Fe is negligible...MR is increasing with increase in CNT
 
You achieved positive MR only after Fe was added, so it's not a weak antilocalization effect in carbon?

EDIT: Probably not due to room temperature...
 
Last edited:
positive MR was achieved with Fe. no MR was observed in case of just CNTs. positive MR was observed when CNT concentration was fixed and Fe increased and also when Fe concentration was fixed and CNT increased. what could be the reason??
 

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