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Remote control of magnetostriction-based nanocontacts at room temperature.

Jammalamadaka SN, Kuntz S, Berg O, Kittler W, Kannan UM, Chelvane JA, Sürgers C - Sci Rep (2015)

Bottom Line: This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials.Investigating the conductance in the regime of electron tunneling by mechanical or magnetostrictive control of the electrode separation enables an estimation of the magnetostriction.The present results pave the way to utilize the material in devices based on nano-electromechanical systems operating at room temperature.

View Article: PubMed Central - PubMed

Affiliation: Magnetic Materials and Device Physics Laboratory, Department of Physics, Indian Institute of Technology Hyderabad, Hyderabad 502 205, India.

ABSTRACT
The remote control of the electrical conductance through nanosized junctions at room temperature will play an important role in future nano-electromechanical systems and electronic devices. This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials. Here we report on the electrical conductance of magnetic nanocontacts obtained from wires of the giant magnetostrictive compound Tb0.3Dy0.7Fe1.95 as an active element in a mechanically controlled break-junction device. The nanocontacts are reproducibly switched at room temperature between "open" (zero conductance) and "closed" (nonzero conductance) states by variation of a magnetic field applied perpendicularly to the long wire axis. Conductance measurements in a magnetic field oriented parallel to the long wire axis exhibit a different behaviour where the conductance switches between both states only in a limited field range close to the coercive field. Investigating the conductance in the regime of electron tunneling by mechanical or magnetostrictive control of the electrode separation enables an estimation of the magnetostriction. The present results pave the way to utilize the material in devices based on nano-electromechanical systems operating at room temperature.

No MeSH data available.


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Magnetostriction-controlled conductance switching of Tb0.3Dy0.7Fe1.95 at room temperature.(a) Semi-logarithmic plot of the conductance G in a magnetic field Hz applied along the z axis. Cycles 2 and 3 have been successively shifted downward by one decade with respect to cycle 1 for clarity. Cartoons visualize the contact configuration in magnetic field due to magnetostriction. (b) Magnetization M vs. Hz. (c) calculated from M(Hz) (solid line) shows the qualitative behaviour of the magnetostrictive strain λz in Hz. The corresponding strain along the wire axis (dashed line) is approximated by λx = −λz/2.
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f3: Magnetostriction-controlled conductance switching of Tb0.3Dy0.7Fe1.95 at room temperature.(a) Semi-logarithmic plot of the conductance G in a magnetic field Hz applied along the z axis. Cycles 2 and 3 have been successively shifted downward by one decade with respect to cycle 1 for clarity. Cartoons visualize the contact configuration in magnetic field due to magnetostriction. (b) Magnetization M vs. Hz. (c) calculated from M(Hz) (solid line) shows the qualitative behaviour of the magnetostrictive strain λz in Hz. The corresponding strain along the wire axis (dashed line) is approximated by λx = −λz/2.

Mentions: Figure 3(a) shows the electrical conductance G vs. magnetic field H for a grain oriented Tb0.3Dy0.7Fe1.95 break junction at room temperature with the magnetic field applied in the z direction. Initially, the junction was adjusted to be in weak contact at G ≈ 100–1000 G0 by mechanically bending the substrate. This conductance corresponds to a junction with a contact diameter of a few nm3. After a few cycles of initial switching without hysteresis the contact reproducibly switches from a “closed” (G > 0) to an “open” (G = 0) state when the magnetic field increases from zero to above 0.5 T. The finite conductance of ≈ 10−2G/G0 measured in the open state is due to the 1 MΩ resistor connected in parallel to the device, see Methods section. The arrows in the graph indicate the evolution of the conductance during the field sweep. The device configuration at each state is visualized by cartoons (brown colour). This switching behaviour of the conductance was measured several times and was established on several samples. The field dependence of the magnetization M in a magnetic field Hz oriented perpendicularly to the long wire axis shows a hard-axis behaviour, see Fig. 3(b).


Remote control of magnetostriction-based nanocontacts at room temperature.

Jammalamadaka SN, Kuntz S, Berg O, Kittler W, Kannan UM, Chelvane JA, Sürgers C - Sci Rep (2015)

Magnetostriction-controlled conductance switching of Tb0.3Dy0.7Fe1.95 at room temperature.(a) Semi-logarithmic plot of the conductance G in a magnetic field Hz applied along the z axis. Cycles 2 and 3 have been successively shifted downward by one decade with respect to cycle 1 for clarity. Cartoons visualize the contact configuration in magnetic field due to magnetostriction. (b) Magnetization M vs. Hz. (c) calculated from M(Hz) (solid line) shows the qualitative behaviour of the magnetostrictive strain λz in Hz. The corresponding strain along the wire axis (dashed line) is approximated by λx = −λz/2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555029&req=5

f3: Magnetostriction-controlled conductance switching of Tb0.3Dy0.7Fe1.95 at room temperature.(a) Semi-logarithmic plot of the conductance G in a magnetic field Hz applied along the z axis. Cycles 2 and 3 have been successively shifted downward by one decade with respect to cycle 1 for clarity. Cartoons visualize the contact configuration in magnetic field due to magnetostriction. (b) Magnetization M vs. Hz. (c) calculated from M(Hz) (solid line) shows the qualitative behaviour of the magnetostrictive strain λz in Hz. The corresponding strain along the wire axis (dashed line) is approximated by λx = −λz/2.
Mentions: Figure 3(a) shows the electrical conductance G vs. magnetic field H for a grain oriented Tb0.3Dy0.7Fe1.95 break junction at room temperature with the magnetic field applied in the z direction. Initially, the junction was adjusted to be in weak contact at G ≈ 100–1000 G0 by mechanically bending the substrate. This conductance corresponds to a junction with a contact diameter of a few nm3. After a few cycles of initial switching without hysteresis the contact reproducibly switches from a “closed” (G > 0) to an “open” (G = 0) state when the magnetic field increases from zero to above 0.5 T. The finite conductance of ≈ 10−2G/G0 measured in the open state is due to the 1 MΩ resistor connected in parallel to the device, see Methods section. The arrows in the graph indicate the evolution of the conductance during the field sweep. The device configuration at each state is visualized by cartoons (brown colour). This switching behaviour of the conductance was measured several times and was established on several samples. The field dependence of the magnetization M in a magnetic field Hz oriented perpendicularly to the long wire axis shows a hard-axis behaviour, see Fig. 3(b).

Bottom Line: This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials.Investigating the conductance in the regime of electron tunneling by mechanical or magnetostrictive control of the electrode separation enables an estimation of the magnetostriction.The present results pave the way to utilize the material in devices based on nano-electromechanical systems operating at room temperature.

View Article: PubMed Central - PubMed

Affiliation: Magnetic Materials and Device Physics Laboratory, Department of Physics, Indian Institute of Technology Hyderabad, Hyderabad 502 205, India.

ABSTRACT
The remote control of the electrical conductance through nanosized junctions at room temperature will play an important role in future nano-electromechanical systems and electronic devices. This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials. Here we report on the electrical conductance of magnetic nanocontacts obtained from wires of the giant magnetostrictive compound Tb0.3Dy0.7Fe1.95 as an active element in a mechanically controlled break-junction device. The nanocontacts are reproducibly switched at room temperature between "open" (zero conductance) and "closed" (nonzero conductance) states by variation of a magnetic field applied perpendicularly to the long wire axis. Conductance measurements in a magnetic field oriented parallel to the long wire axis exhibit a different behaviour where the conductance switches between both states only in a limited field range close to the coercive field. Investigating the conductance in the regime of electron tunneling by mechanical or magnetostrictive control of the electrode separation enables an estimation of the magnetostriction. The present results pave the way to utilize the material in devices based on nano-electromechanical systems operating at room temperature.

No MeSH data available.


Related in: MedlinePlus