Europhys. Lett.
Volume 63, Number 1, July 2003
Page(s) 104 - 110
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 June 2003
DOI: 10.1209/epl/i2003-00484-4
Europhys. Lett., 63 (1) , pp. 104-110 (2003)

Origin of temperature dependence in tunneling magnetoresistance

J. J. Åkerman1, 2, I. V. Roshchin1, J. M. Slaughter2, R. W. Dave2 and I. K. Schuller1

1  Physics Department 0319, University of California San Diego La Jolla, CA 92093-0319, USA
2  Motorola Labs, Physical Sciences Research Laboratories - Tempe, AZ 85284, USA

(Received 4 November 2002; accepted in final form 25 April 2003)

We present detailed measurements of the differential resistance ( $\upd V/\upd I$) of state-of-the-art $\chem{FM/AlO}$ x/ $\chem{FM}$ magnetic tunnel junctions (MTJ) as a function of applied bias and temperature. Temperature effects are particularly significant in physical quantities involving narrow features such as those at low-voltage bias. We show that the temperature evolution of the tunneling characteristics and, in particular, the pronounced rounding of the $\upd V/\upd I$ curves with increasing temperature can be well explained by thermal smearing of the tunneling electron energy distribution.

73.40.Gk - Tunneling.
73.40.Rw - Metal-insulator-metal structures.
75.70.Pa - Giant magnetoresistance.

© EDP Sciences 2003