Magnetotransport properties of Pr0.67Sr0.33MnO3 nanobridge
Abstract
We have previously obtained a large low-field magnetoresistance (LFMR) in compressive strained Pr_0.67Sr_0.33MnO3 (PSMO) thin films, which has much larger magnetoresistance (MR) ratio than that of GMR and TMR systems. The effect is identified to be associated with the unconventional magnetic domain walls of the thin films which have perpendicular stripe domains. In order to understand the origin of the large domain wall resistance (DWR) effect, we studied the MR properties of the PSMO nanobridges, which have the size of 500 nm - 5 micron long and 300 nm - 5 micron wide made using e-beam lithography. We found that, the PSMO nanobridge sample maintains all the LFMR and DWR properties as in the un-patterned PSMO thin films, and it shows the nonlinear I-V characteristics below T_c. The I-V curves were fitted very well with the Simmons tunneling model, which indicates that tunneling is a dominant factor in the transport property. This indicates there are mixed-phase states in the sample with ferromagnetic conducting phase and antiferromagnetic insulating phase. The dependence of the tunneling barrier height and thickness as the function of the temperature and in the different demagnetized states are studied and the results will be discussed based on the model proposed by Golosov[1] on the insulating stripe domain walls in the system. [1] D. I. Golosov, Phys. Rev. B 67, 064404 (2003).
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARY24007H