Extraordinary magnetoresistance: sensing the future

• Authors: Thomas Hewett , Feodor Kusmartsev
• Languages of publication: EN

Abstracts

EN

Simulations utilising the finite element method (FEM) have been produced in order to investigate aspects of circular extraordinary magnetoresistance (EMR) devices. The effect of three specific features on the resultant magnetoresistance were investigated: the ratio of the metallic to semiconducting conductivities (σ
M/σ
S); the semiconductor mobility; and the introduction of an intermediate region at the semiconductormetal interface in order to simulate a contact resistance. In order to obtain a large EMR effect the conductivity ratio (σ
M/σ
S) is required to be larger than two orders of magnitude; below this critical value the resultant magnetoresistance effect is dramatically reduced. Large mobility semiconductors exhibit larger EMR values for a given field (below saturation) and reduce the magnetic field required to produce saturation of the magnetoresistance. This is due to a larger Hall angle produced at a given magnetic field and is consistent with the mechanism of the EMR effect. Since practical magnetic field sensors are required to operate at low magnetic fields, high mobility semiconductors are required in the production of more sensitive EMR sensors. The formation of a Schottky barrier at the semiconductor-metal interface has been modelled with the introduction of a contact resistance at the semiconductor-metal interface. Increasing values of contact resistance are found to reduce the EMR effect with it disappearing altogether for large values. This has been shown explicitly by looking at the current flow in the system and is consistent with the mechanism of the EMR effect. The interface resistance was used to fit the simulated model to existing experimental data. The best fit occurred with an interface with resistivity of 1.55×10−4 m (overestimate). The EMR effect holds great potential with regard to its future application to magnetic field sensors. The design of any such devices should incorporate high mobility materials (such as graphene) along with the specific features presented in this paper in order to produce effective magnetic field sensors.

Keywords

EN

extraordinary magnetoresistance; interface resistance; magnetotransport; graphene

• Publisher: De Gruyter Open
• Journal: Open Physics
• Year: 2012
• Volume: 10
• Issue: 3
• Pages: 602-608

Dates

published

1 - 6 - 2012

online

17 - 6 - 2012

Contributors

author

Thomas Hewett

• Department of Physics, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK

author

Feodor Kusmartsev

• Department of Physics, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK

References

• [1] S. A. Solin, T. Thio, D. R. Hines, J. J. Heremans, Science 289, 1530 (2000) http://dx.doi.org/10.1126/science.289.5484.1530[Crossref]
• [2] S. A. Solin, Sci. Am. 291, 70 (2004) http://dx.doi.org/10.1038/scientificamerican0704-70[Crossref]
• [3] T. Zhou, D. R. Hines, S. A. Solin, Appl. Phys. Lett. 78, 667 (2001) http://dx.doi.org/10.1063/1.1343472[Crossref]
• [4] S. A. Solin et al., IEEE Trans. Magn. 38, 89 (2002) http://dx.doi.org/10.1109/TMAG.2002.988917[Crossref]
• [5] S. A. Solin et al., Appl. Phys. Lett. 80, 4012 (2002) http://dx.doi.org/10.1063/1.1481238[Crossref]
• [6] J. Suh, W. Kim, J. Chang, S. H. Han, E. K. Kim, J. Korean. Phys. Soc. 55, 577 (2009) http://dx.doi.org/10.3938/jkps.55.577[Crossref]
• [7] A. L. Friedman, J. T. Robinson, F. K. Perkins, P. M. Campbell, Appl. Phys. Lett. 99, 022108 (2011) http://dx.doi.org/10.1063/1.3610565[Crossref]
• [8] J. Lu et al., Nano Lett. 11, 2973 (2011) http://dx.doi.org/10.1021/nl201538m[Crossref]
• [9] C. H. Möller et al., Appl. Phys. Lett. 80, 3988 (2002) http://dx.doi.org/10.1063/1.1481982[Crossref]
• [10] T. H. Hewett, F. V. Kusmartsev, Int. J. Mod. Phys. B. 23, 4158 (2009) http://dx.doi.org/10.1142/S0217979209063341[Crossref]
• [11] T. H. Hewett, F. V. Kusmartsev, Phys. Rev. B 82, 212404 (2010) http://dx.doi.org/10.1103/PhysRevB.82.212404[Crossref]
• [12] J. Moussa et al., Phys. Rev. B 64, 184410 (2001) http://dx.doi.org/10.1103/PhysRevB.64.184410[Crossref]
• [13] J. Moussa, L. R. Ram-Mohan, A. C. H. Rowe, S. A. Solin, J. Appl. Phys. 94, 1110 (2003) http://dx.doi.org/10.1063/1.1576897[Crossref]
• [14] C. B. Rong, H. W. Zhang, J. r. Sun, B. G. Shen, J. Magn. Magn. Mater. 301, 407 (2006) http://dx.doi.org/10.1016/j.jmmm.2005.07.017[Crossref]
• [15] C. H. Möller, D. Grundler, O. Kronenworth, C. Heyn, D. Heitmann, J. Supercond. 16, 195 (2003) http://dx.doi.org/10.1023/A:1023246431624[Crossref]
• [16] M. Holz, O. Kronenworth, D. Grundler, Phys. Rev. B. 67, 195312 (2003) http://dx.doi.org/10.1103/PhysRevB.67.195312[Crossref]
• [17] M. Holz, O. Kronenworth, D. Grundler, Appl. Phys. Lett. 83, 3344 (2003) http://dx.doi.org/10.1063/1.1621077[Crossref]
• [18] M. Holz, O. Kronenworth, D. Grundler, Physica E 21, 897 (2004) http://dx.doi.org/10.1016/j.physe.2003.11.146[Crossref]
• [19] K. S. Novoselov et al., Science 306, 666 (2004) http://dx.doi.org/10.1126/science.1102896[Crossref]
• [20] K. S. Novoselov et al., P. Natl. Acad. Sci. USA 102, 0451 (2005) http://dx.doi.org/10.1073/pnas.0502848102[Crossref]
• [21] F. V. Kusmartsev, A. M. Tsvelick, Pis’ma Zh. Eksp. Teor. Fiz. 42, 207 (1986)
• [22] T. H. Hewett, M. B. Gaifullin, F. A. Mamari, O. E. Kusmartseva and F. V. Kusmartsev, Preprint, Loughborough University (2012)
• [23] A. O’Hare, F. V. Kusmartsev, and K. I. Kugel, Nano Lett. doi:10.1021/nl204283q (2012) [Crossref]
• [24] S. A. Bulgadaev and F. V. Kusmartsev, Phys. Lett. A 342, 188 (2005). http://dx.doi.org/10.1016/j.physleta.2005.04.096[Crossref]
• [25] L. J. van der Pauw, Philips Tech. Rev. 20, 220 (1958)

Identifiers

DOI

10.2478/s11534-012-0015-1