Magnetoresistance of the thin film ferromagnetic nanoconstrictions

• Published in: Chinese science bulletin 2012-02, Vol.57 (5), p.445-449
• Main Authors: Cheng, Hao, Yang, Wei, Liu, Hong, Wang, LingJiang
• Format: Article
• Language: English
• Subjects: Chemistry/Food Science; Earth Sciences; Electrodes; Engineering; Ferromagnetic materials; films (materials); Humanities and Social Sciences; iron; Life Sciences; magnetism; Magnetoresistance; Magnetoresistivity; multidisciplinary; Nanocomposites; Nanomaterials; Nanostructure; nanotechnology; Physics; Science; Science (multidisciplinary); temperature; Thin films; 电子束光刻; 电阻薄膜; 磁各向异性; 磁电阻比; 磁阻; 薄膜沉积; 铁磁电极; 铁磁薄膜
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-011-4881-5

The magnetoresistance and I-V characteristics at different temperatures of the thin film ferromagnetic nanoconstrictions of varia- ble width （from 20 to 250 rim） and 10 nm thicknesses, fabricated by electron beam lithography and vacuum thin film deposition are compared. The magnetoresistance and resistance of the thin film ferromagnetic nanoconstrictions are not related to the width of the nanoconstrictions. Instead the resistance of the local nano-region in the middle of the thin film ferromagnetic nanocon- striction has only a minor role compared to that of the two microscale thin film ferromagnetic electrodes, which contribute the majority of the measured resistance. The magnetoresistances of the thin film ferromagnetic nanoconstrictions and a 0.2 cmx 0.8 cm thin ferromagnetic film deposited under the same conditions were also compared; the thin film ferromagnetic nanocon- strictions have higher magnetoresistances than the thin ferromagnetic film, which implies that the measured magnetoresistance of the thin film ferromagnetic nanoconstrictions comes mainly from the local nano-region in their centers. In conclusion, the meas- ured magnetoresistance of the whole sample is similar to the anisotropic magnetoresistance, because the resistance of the two microscale thin film ferromagnetic electrodes is much higher than that of the local nano-region in the middle of the samples. Comparing the experimental results for the thin film ferromagnetic nanoconstrictions and the thin ferromagnetic film reveals that the magnetoresistance of the local nano-region in the middle of the sample is much higher than that of the two microscale thin film ferromagnetic electrodes attached to it.