Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-14T10:08:07.251Z Has data issue: false hasContentIssue false
  • English
  • Français

Giant ac electrical response of La0.7Sr0.3MnO3 in sub-kilogauss magnetic fields

Published online by Cambridge University Press:  01 February 2011

Alwyn Rebello ,
Vinayak Bharat Naik ,
Sujit Kumar Barik ,
Mark Choong Lam  and
Mahendiran Ramanathan
Alwyn Rebello
Affiliation:
alwyn@nus.edu.sg, National University of Singapore, Department of Physics, Singapore, Singapore
Vinayak Bharat Naik
Affiliation:
naik@nus.edu.sg, Natioanl University of Singapore, Department of Physics, Singapore, Singapore
Sujit Kumar Barik
Affiliation:
skbarik@nus.edu.sg, National University of Singapore, Department of Physics, Singapore, Singapore
Mark Choong Lam
Affiliation:
g0806648@nus.edu.sg, National University of Singapore, Department of Physics, Singapore, Singapore
Mahendiran Ramanathan
Affiliation:
phyrm@nus.edu.sg
Get access

Abstract

We report ac electrical transport in the metallic ferromagnet La0.7Sr0.3MnO3. Both ac resistance (R) and reactance (X) were measured as a function of temperature (T= 400-100 K), frequency of the ac current (f = 100 kHz – 20 MHZ) and external dc magnetic field (H = 0-100 mT) applied parallel to the current direction. It is shown that, while R(H = 0 T) decreases smoothly around the Curie temperature (TC) for f = 100 kHz, an abrupt increase followed by a peak close to TC occurs for f ≥ 500 kHz. The peak decreases in magnitude, broadens and shifts down in temperature with increasing values of H. The peak in R is completely suppressed under H= 100 mT resulting in a huge low-field ac magnetoresistance (R/R= -53 % for f= 2MHz) whereas the dc magnetoresistance only -31 % even at H = 7 T. While the reactance X(H = 0 T) also shows an abrupt increase at TC for f < 10 MHz, it decreases abruptly at TC for f ≥ 12 MHz. The magnetoreactance is largest (X/X= -47 %) at f = 100 kHz and it changes sign from negative to positive with increasing frequency. It is suggested that the observed huge ac magnetoresistance arises from decrease of magnetic permeability which enhances skin depth under a magnetic field. Our results indicate that the extraordinary sensitivity of the ac magnetoresistance to low dc magnetic fields can be exploited for device applications.

Keywords

magnetoresistance (transport)magnetoresistance (magnetic)magnetic properties
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1256: Symposium N – Functional Oxide Nanostructures and Heterostructures , 2010 , 1256-N04-01
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Tokura, Y. (Ed.), Colossal Magnetoresistive Oxides (Gordon & Breach, Singapore, 2000).Google Scholar
2 Dagotto, E., Nanoscale Phase Separation and Colossal Magnetoresistance (Springer-Verlag, Berlin, 2003).Google Scholar
3 Philipp, J. B., Höfener, C., Thienhaus, S., Klein, J., Alff, L., and Gross, R., Phys. Rev. B 62 R9248 (2000).Google Scholar
4 Bowen, M., Bibes, M., Barthélémy, A., Contour, J.- P., Anane, A., Lemaitre, Y., and Fert, A., Appl. Phys. Lett. 82, 233 (2003).Google Scholar
5 Wang, L. M., Liu, Chen-Chung, Yang, H. C., and Horng, H. E., J. Appl. Phys. 95, 4928 (2004).Google Scholar
6 Mahesh, R., Mahendiran, R., Raychaudhuri, A. K., and Rao, C.N.R., Appl. Phys. Lett. 68, 2291, (1996).Google Scholar
7 Gupta, A., Gong, G. Q., Xiao, G., Duncombe, P. R., Lecoeur, P., Trouilloud, P., Wang, Y. Y., Dravid, V. P., and Sun, J. Z., Phys. Rev. B 54, R15629 (1996)Google Scholar
8 Hwang, H. Y., Cheong, S. -W., Ong, N. P., and Batlogg, B., Phys. Rev. Lett. 77, 2041 (1996).Google Scholar
9 Lofland, S. E., Bhagat, S. M., Tyagi, S. D., Mukovskii, Y. M., Karabashev, S. G., and Balbashov, A. M., J. Appl. Phys. 80, 3592 (1996)Google Scholar
10 Srinivasu, V. V., Lofland, S. E., and Bhagat, S. M., J. Appl. Phys. 83, 2866 (1998).Google Scholar
11 Fu, M., Hsu, K. S., Lin, M.L., and Wen, Z. H.. J. Magn. Magn. Mater. 209, 154 (2000).Google Scholar
12 Qin, C. H., Hu, J., Chen, J., Wang, Y., and Wang, Z., J. Appl. Phys. 91, 10003 (2002).Google Scholar
13 Castro, G. M. B., Rodrigues, A. R., Machado, F. L. A., and Jardim, R. F., J. Magn. Magn.Mater. 272, 1848 (2004)Google Scholar
14 Dutta, P., Dey, P. and Nath, T. K., J. Appl. Phys. 102, 073906 (2007); S. K. Ghatak, B. Kaviraj, and T. K. Dey, ibid. 101, 023910 (2007).Google Scholar
15 Souza, J. A., Jardim, R. F., Muccillo, R., Muccillo, E. N. S., Torikachvilli, M. S., and Neumeier, J. J., J. App. Phys. 89, 6636 (2001)Google Scholar
16 Rebello, A., Naik, V. B. and Mahendiran, R., J. Appl. Phys. 106, 073905 (2009).Google Scholar
17 Majumdar, P. and Littlewood, P. B., Nature (London) 395, 479 (1998).Google Scholar
18 Mahendiran, R., and Schiffer, P., Phys. Rev. B 68, 024427 (2003); T. Brown, W. Li, H. P. Kunkel, X. Z. Zhou, G. Williams, Y. Mukovskii, and A. Arsenov, J. Phys.: Condens. Matter 17, 5997 (2005).Google Scholar
19 Landau, L.D., Lifshitz, E.M. and Pitaevskii, L. P., Electrodynamics of Continuous Media, 2nd edition, (Butterworth-Heinemann, Oxford, 2004) pg. 212.Google Scholar
20 Srikanth, H., Wiggins, J., and Rees, H., Rev. Sci. Instr. 70, 3097 (1999).Google Scholar
21 Panina, L. V., Mohri, K., Uchiyama, T., Noda, M., and Bushida, K., IEEE Trans. Magn. 31, 1249 (1995).Google Scholar
22 Knobel, M., Vázquez, M., and Kraus, L., in Handbook of Magnetic Materials, edited by Buschow, K. H. J. (Elsevier, Amsterdam, 2003), Vol. 15, pp. 497–563, and references therein.Google Scholar
23 Wang, J., Ni, G., Gao, W., Gu, B., Chen, X., Du, Y., Phys. Stat. Sol. (a), 183 421 (2001).Google Scholar
24 Barandiarán, J. M., Garcia-Arribas, A., and Cos, D. de, J. Appl. Phys. 99, 103904 (2006).Google Scholar
25 Rebello, A. and Mahendiran, R., Appl. Phys. Lett. 96, 032502 (2010).Google Scholar