Limits...
Electrical characterization of gold-DNA-gold structures in presence of an external magnetic field by means of I-V curve analysis.

Khatir NM, Banihashemian SM, Periasamy V, Ritikos R, Abd Majid WH, Abdul Rahman S - Sensors (Basel) (2012)

Bottom Line: The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field.This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction.The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors.

View Article: PubMed Central - PubMed

Affiliation: Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, Kuala Lumpur, Malaysia. mahmoudy_phy@yahoo.com

ABSTRACT
This work presents an experimental study of gold-DNA-gold structures in the presence and absence of external magnetic fields with strengths less than 1,200.00 mT. The DNA strands, extracted by standard method were used to fabricate a Metal-DNA-Metal (MDM) structure. Its electric behavior when subjected to a magnetic field was studied through its current-voltage (I-V) curve. Acquisition of the I-V curve demonstrated that DNA as a semiconductor exhibits diode behavior in the MDM structure. The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field. This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction. The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors.

Show MeSH

Related in: MedlinePlus

I(B=0)-I(B) via voltage in the presence of various magnetic field for gold-DNA-gold structure.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3376582&req=5

f5-sensors-12-03578: I(B=0)-I(B) via voltage in the presence of various magnetic field for gold-DNA-gold structure.

Mentions: Once an external magnetic field is applied to the semiconductor, the energy levels increased allowing some of them to pass above the Fermi energy. In high magnetic field, the scattering amplitude for similar and dissimilar spins will differ [16] and the band gap will change according to discrete energy levels. In the presence of some low magnetic fields, the band gap does not change considerably. Also, the charge of material in a magnetic field will be subjected to a Lorentz force and Drude Theory. Electrons in partially filled bands and ions could be affected by the external magnetic field. A circular motion will be created with a trajectory of electron that is perpendicular to the field. Additionally, In Metal-DNA-Metal structures, before the charge carriers migrate from the left electrode to the right one, they move in a disturbed and spiral fashion to left and right for many times [14]. Such disturbed movements are due to the loose coupling of electrodes and DNA. In summary, an external magnetic field, alters the motion of carriers alongside the electric field and inhibits the reach of the carriers to the opposite electrode. This results in a decrease in current with respect to the case for absence of a magnetic field. To closer investigation of variations of current in present of magnetic field, differential current through MDM in presence and absence of magnetic field (I(B=0)-I(B)) versus voltage is illustrated in Figure 5. As seen, a gradual decline in current occurs with increase of field strength. It is known from this figure that in absence of magnetic field the current exceeds that of in its presence which results in a positive differential current in forward bias and negative in reverse. Therefore, the difference between the current in presence and absence of a magnetic field for greater magnetic fields increases and magnetic resistance rises with the field strength.


Electrical characterization of gold-DNA-gold structures in presence of an external magnetic field by means of I-V curve analysis.

Khatir NM, Banihashemian SM, Periasamy V, Ritikos R, Abd Majid WH, Abdul Rahman S - Sensors (Basel) (2012)

I(B=0)-I(B) via voltage in the presence of various magnetic field for gold-DNA-gold structure.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376582&req=5

f5-sensors-12-03578: I(B=0)-I(B) via voltage in the presence of various magnetic field for gold-DNA-gold structure.
Mentions: Once an external magnetic field is applied to the semiconductor, the energy levels increased allowing some of them to pass above the Fermi energy. In high magnetic field, the scattering amplitude for similar and dissimilar spins will differ [16] and the band gap will change according to discrete energy levels. In the presence of some low magnetic fields, the band gap does not change considerably. Also, the charge of material in a magnetic field will be subjected to a Lorentz force and Drude Theory. Electrons in partially filled bands and ions could be affected by the external magnetic field. A circular motion will be created with a trajectory of electron that is perpendicular to the field. Additionally, In Metal-DNA-Metal structures, before the charge carriers migrate from the left electrode to the right one, they move in a disturbed and spiral fashion to left and right for many times [14]. Such disturbed movements are due to the loose coupling of electrodes and DNA. In summary, an external magnetic field, alters the motion of carriers alongside the electric field and inhibits the reach of the carriers to the opposite electrode. This results in a decrease in current with respect to the case for absence of a magnetic field. To closer investigation of variations of current in present of magnetic field, differential current through MDM in presence and absence of magnetic field (I(B=0)-I(B)) versus voltage is illustrated in Figure 5. As seen, a gradual decline in current occurs with increase of field strength. It is known from this figure that in absence of magnetic field the current exceeds that of in its presence which results in a positive differential current in forward bias and negative in reverse. Therefore, the difference between the current in presence and absence of a magnetic field for greater magnetic fields increases and magnetic resistance rises with the field strength.

Bottom Line: The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field.This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction.The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors.

View Article: PubMed Central - PubMed

Affiliation: Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, Kuala Lumpur, Malaysia. mahmoudy_phy@yahoo.com

ABSTRACT
This work presents an experimental study of gold-DNA-gold structures in the presence and absence of external magnetic fields with strengths less than 1,200.00 mT. The DNA strands, extracted by standard method were used to fabricate a Metal-DNA-Metal (MDM) structure. Its electric behavior when subjected to a magnetic field was studied through its current-voltage (I-V) curve. Acquisition of the I-V curve demonstrated that DNA as a semiconductor exhibits diode behavior in the MDM structure. The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field. This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction. The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors.

Show MeSH
Related in: MedlinePlus